If u have been casting over heads for awhile u will be able to cast the torium 50 on the right rod and when loaded up correctly - u wont cast it as far as the 30 tho .....

The shimo 30 size reels or the daiwa 50 size reels is all u need to stop most noahs , braid backing and a top shot. If u planning on swimming a ray/shark for BIG sharks then u would want more line 1200m plus , but some times that still is not enough , some sharks are just not meant to be landed and will take all the line off your reel with out even knowing that it has been hooked.

Mate i have just brought a saltiga 50...... its is an awesome reel!! great to cast i have matched it to a poisiden bantam 5.

I wou ld never look back, i have got 700m+ of 50lb braid and 9m of 150lb wind on.

I know my former boss used to use an old Penn Senator 114h 6/0 on a 13ft broomstick of a rod(think it might have been a Snyder or Ozflex). He used from memory 50lb mono and used to use half a salmon or whole 50cm sized Tailor. He was a master of casting though, employing alot of the South African casting techniques to get it out a fair way. About the same distance i could manage with casting a herring bait out on a spinning reel.

It was low mounted on the rod and he actually cupped his hand over the top of the reel, with his thumb at the front and his fingers at the back to cast it. Not the usual holding the rod and using your thumb casting method.

But again not an easy task to do what he did with that sized reel. He also told me he could do it with a TLD 25 aswell.

 I have a torium 50 with 1300m on it, I only got this reel because I can still slidebait, kayak, balloon and swim bait all with the same reel, as mentioned above the smaller reels do cast further ( I get 100m max out of a cast with an 8oz grapnel), a 3m shark is well and truly a possibility on a torium 30 or similar sized reel, but even with this much line there is some things that just make your gear feel inadequate and I'm going to be looking at a bigger setup soon for chasing even bigger stuff.

you can cast up to about a 4/0 Penn without having to learn too much new stuff about casting big o/heads.  Bigger than that you will need to learn a new cast - a sideways heave.  Consider 2 things:

If you want a big bait out there google slide-baiting and do some research on the 'net.   You will keep the size and cost of your tackle to happy minimums.   And you can get a huge bait (not castable under any circumstances) out 100m plus on this tackle.  Braid backing of 600 to 800 m plus a topshot of say 200m of 0.55mm to 0.60mm nylon (which you can fit on the quite modest sized Saltist 50's etc) will stop a huge shark if you are up to fishing it to the full strength of that tackle.  Be warned - it is not everyone who can manage 10 to 15 kg of drag off a big surfstick for a few hours on end.

Also, be real - we get huge whaler sharks along our coast, as well as the occasional GW.  These creatures not going to come out except by fluke.  The old-timers fishing near whaling stations (in SA) used to use a technique that had the fish swallow the bait, then hooked in stomach which was then dragged forward in the fish, suffocating it over  a relatively short time.  That is what it took to land fish well over 450kg.  Pretty ugly and not something I'd be happy to see again.

If you decide to go for casting then practice will be required.  So get yourself an 8oz sinker and a size 10 running shoe on a short dropper and start to learn how to do a sidecast.  When you get proficient you can fill the shoe with sand for a bit more of a realistic weight.  Start with your back to the sea and the tackle lying on the ground .  You are going to do an "off-the-ground" cast backwards, because that is a whole lot easier on the back and arms.  Turn and lift into the cast to get it going and as someone here has said, brake with your whole hand cupping the spool.