jig weight depends on wind and tide at the time but it can get quite expensive with the sharks taking most of the fish .
Been going there for 20 years and it gets worse every year .Just got back from a 3 week trip up there . Hard enough to beat the sharks up from 20mtrs some times and I don't bother fishing over 70mtrs these days to give some hope of landing a fish . 90% of my fishing up there is now trolling for billfish as its too hard to get a fish past the sharks when bottom bashing .
Probably not what you want to hear but is the reality of the area these days.

 Cheers mate, I have fished there before but havent given it a go past 80m mark so just trying to make sure i will have heavy enough jigs and enough of them.

 yep very hard to say depends so much on boat, para anchor, wind etc.

but in saying that jigged well with 150 in 100m with PE 2.5 but on big boat not often I go past 250gs.

Sharks blrrrrrr.  starting to get impossible for more that one drop in a spot these days

 Use the cheapest jigs you have or You mite aswell throw $50 Bill's over the side. 

 no jigs big baits and wind like crazy 

I vary rarely jig in over 80mtrs up here anymore as its rare to get goldband on the jig and more chances of hooking Amberjack which is fun but they don't go in the esky. Have hooked reds out that deep but rare.

I have more luck jigging 70 - 85 meters and if you get sharked move on. Some days are better then others but unless you travel away from known areas you will get sharked. And as the others have said stock up on cheap jigs. The heaviest I use is about 150 gram but mostly 80 to 120 gram. Also make sure your assist hooks are heavy duty, I have straitened a lot of quality known brands on big reds and Rankin so make my own now with live bait hooks. You have to lock up and go hard to beat the sharks. I don't get as many fish as I do on bait but I get more quality.

 Cheers mate good info there, I was hoping to get goldband on a jig in that depth but now youve got me rethinking.

Most of our fishing will be between 40-80m anyway but thought it may be worth a crack out deeper to try for a goldy.

FWIW Have caught plenty of goldband on jigs around the 100m mark.  have found fast jigging much more successfull for them though

We didnt get any fish sharked. We were borderline speed jigging and hooking up rankins / coro's about 5-7 off bottom with Dhubites between 150-300g. Then just dont let them turn their head, make sure you have a reel with 100cm per wind. You can usually stop the head turns if you ditch the lift and wind method and replace it with the no lift / constant wind with maxed drag. The head start on the sharks helps a lot. There were sharks around because we had a couple take the jig on the drop.