Can't really go wrong with Furuno, Simrad or Garmin. I would go 2x smaller screens over a 16". Im running 2x 10" Garmin 7410xsvs. Flush mount screens are best. I would still intergrate your yammy up to the Mfds. Relatively cheap and the fuel management info you get on the screens is awesome.

See if carribean will help accomodate with the bilge layout and trailer to allow a thru hull transducer with a fairing. Easily the best performance reading at speed and will help you find more ground

nice choice with the boat mate! 

I just got my mitts on a Simrad nss Evo3 12 inch with a 1kw wet box trannie for my cat project. Gimme about a month and I'll let you know how it goes.

 The new furuno tz3 look pretty impressive. 

 But you will need to make it clear from the outset, so the trailer will fit. I've personally found the Raymarine Axiom gear very good, fully networked. I have had zero problems in two years and 500 hours of operations.  This is probably a bit scary if you are used to old style standalone or combo units, but it is actually easier to use, much easier, when you get the basics. If I go back to an old-style combo on someone elses's boat now, I am tearing my hair out. A million button pushes to do something I can do with one tap on mine. I've just helped a mate set up a 9" Pro with TM265 and Autopilot on his 30 yo Westerberg. He is very happy with it, finds it easy to use.  You are  getting an autopilot? Good. And if you do, get one with a remote head--temptation for some is to get one that is just controlled from the MFD, but having a separate dedicated head is much better, with a knob, particularly if you want to make small course adjustments. It's still all integrated, shared dimming on everything so you can dim the lot from just one screen.

I would personally not recommend touch-only displays--I have one of each, and really do everything I can on the Hybrid-Touch pro, which has buttons and dials as well as touch. Wet fingers and a rolling boat make touch-only an exercise in frustration at times. Couldn't fit two of the Pro's on my dash, unfortunately. 

I'd personally go with two smaller displays, as per Stevo81 above, just my preference. I can't comment for the other brands, but the Raymarine would be very easy to use as a combo, much easier than the old combos. Just tap the screen section you want to control, and all the menus and configurable button pushes swap to that screen. Why would I prefer two smaller rather than one large? Redundancy is one thing, but, in my case, I judged I'd have to be reaching through the wheel to touch anything on the bottom of the screen if I went 12" .  With all of the above systems, once you are networked, you can make any screen show anything. For example, I tend to go out with my smaller screen on dashboard, giving me all my engine info, and the larger one on Plotter. Get near the ground, go to sounder and plotter. 

Congrats on the choice, looking forward to seeing how it goes.

How many do you have ?
More you spend bigger and better you get.
Do your homework.
Watch out for suppliers selling you old models and old stock remember they want to get rid of old and get new stock.
Do I want the latest and the best?
But in saying that you can get a bargain at some places.
Raymarine,Simrad all good,$$$$
https://www.youtube.com/watch?v=YhFzHtfekfs
Technology has come a long way since paper scroll sounders.
1kw Trany Def
12+ screen

P.S

Do I spend less on sounder and put a auto pilot in ? ⚖️

I currently run a Simrad 12" EVO2 and have found it to be great. The lowrance/simrad autopilot is fantastic. I run the TM150 600w Chirp transducer and totalscan and find it great from 10-100m.

If I was buying new and (probably for my next boat) i would install a 2x Simrad GO9XSE. I don't find the touchscreen too much of an issue and use it 99% of the time. 

outboard and it came with a Simrad NSS EVo 3 which has 1 kw capability.  So I bought an Airmar M135C M 1kw in hull transducer and installed it myself, as it comes with its own wetbox.  According to Airmar there is no loss of sensitivity firing through a solid glass hull, just a loss of depth capability  They say that this is capable of about 350 metres or more.  This is medium chirp and you can read the specs yourself with depth and cone angle.  My install reads at any speed ( I don't go over 30 knots) and I have had it reading well at 150 metres, I haven't gone any deeper. but have it running at the same time as a 200/50khz 600w transducer (Lowrance) that i have siliconed in the hull.  They both read exceptionally well, the chirp is more sensitive.   Hope this helps, cost of transducer is about $1100.

 Probably find all brands will mirror to a tablet.I run two networked combos and would not consider a single display. I agree with Ranmar on having combination touch and buttons.

 And, more than that, you can actually control the MFD through your phone, with an app! You can add that the the huge list of largely useless things that have been made available to us in recent years.  I will concede there may be layouts where it could be useful, but certainly not in your average hardtop/cuddy setup.

 Cheers guys,

I was originally thinking of 2 screens then changed my mind to 1 big screen as I can mirror to a device. I was also considering a 2nd sounder on the bait board, but being able to mirror solves that dilemma.

Hmm decisions, I will have to speak with Mansfield about the in hull transducer, and what size screens will fit.

next thing I have to look at is the cost of the engine and trailer through them, as a bit of a google tells me they are taking the piss with what their charging. But then ease of getting it all done in one place and pickup a completed boat has appeal

 Yeah I was looking at the duralites.

this new boat stuff is doing my head in, I thought a new boat would be easy.

inquired with a few companies over different things and most of them don't even get back to me.

might be easier to buy used haha

   yep, it's all down to you , and you have to live with the consequences.  This is the appeal of the whole fixed BMT package to many, just pick one  and drive off.  I tried locally for a trailer, probably a bit late in the process. Some mob up at Wangara who were recommended on here, for an aluminium trailer, after I got the price for the upgraded Reefrunner trailer from Mansfields  (2900kg ATM) . A couple of phone calls with them were just an exercise in frustration, couldn't get past the receptionist who really didn't seem to know what she was talking about. I don't live in Perth, didn't have time to drive around and look at everything, so I just went with the Easytow which are a good reputable brand. And it is a good trailer. 

Mansfields' fit-outs are good--any fibreglass work they do is top notch. Any external stuff which means cutting and grinding of your new boat   will look like it comes out of a mould, can't fault them. They are shipwrights, not just boat dealers. Rigging of the motor and battery instals are likely to be done by whoever is supplying the motor. Not sure who does any ancillary wiring for them, as I did all of my own, and Darren 253 did his. The 2300 is different from the Reefie, I believe, in the access to the rear of the dash and how wiring and components can be managed. 

I found their prices for instals of rod holders, for example, were not cheap--they were using top quality holders, and, after doing it myself, well---their price isn't too bad. i wanted more than the basic 4, so I sourced a mix of  good cast-top holders  and plain welded types ( cast-top for strike rods, the lighter ones just to hold rods) and some cup/sinker holders ( really useful) , and fitted them myself, but it's a fiddly shit of a job in a lot of ways, definitely saved a significant amount of money, but you need to be confident with tools. It's not 'just a hole, anyone can do it" . Tinnys with wide flat-topped coamings are easy, moulded glass coamings, not so much. It probably took me over a day to do six holders and four cupholders? 

It all came down to looking at what they were quoting for a part of the job, and made the decision as to whether I could really do it well, and significantly cheaper--if not, I was happy to give it to them.  

 Yeah, appreciate the comment. Think if I'm going ahead with the 2300 I will just grin and bear it and get Mansfield to do the entire fit out.

doesnt help that I'm currently in Sydney and won't be back in wa until sept/oct which is when I want the boat ready by. Don't wanna screw around inning a boat around getting it finished or doing bits myself.

 Yeah mate I did consider that, but would prefer to be close to the dealer for any warranty that may come up