depends on depth, i use around 150-300g in upto 40-50 meters. If your fishing big depths like we do for sambos over there there 400-500g jigs arent out of the question.

Snapper are hard to get on jigs because if there small hard mouths so id suggest a smaller jig around 150g with an assist hook on the top and a single hook on a split ring on the bottom to increase your chances of hook ups. Never fished specifically for kingies over here due to there not being many but seeing as they school up over there id try a 200g searock for starters- they are a good cheap jig, im a fan of the purple prism color. SWLAB do some nice small jigs too

SWLAB Fat tail 200g

River2Sea Searock 200g

Hi Doro,
I catch a fish that is the same as your snapper.
These fish lay VERY close to structure, and when the tide is pulling, behind and just off the bottom (hope you've got a decent sonar?).
Aim to drop straight into the 'zone' or within 3-5 feet of it, then you will get an immediate hit (if they are in the mood) and if you use the right jig.
I have a pink/silver/white Sea Rock (same model as above, 2nd up) in 90gm that has been well and truely blitzed by snapper recently, it has teeth still buried in it - thats how hard they grab a jig! (And sea rocks aren't soft either).
Hits will come before you get into the 'zone' so watch out for the line stopping coming off the spool.
Use whatever weight of Sea Rock jig as above that will go straight into the 'zone' almost vertically. Get plenty of jigs cuz you will loose a few if your gonna catch the better fish, I have no trade connection they're just very good for snapper.
I use one Mustad 10829BLN 4/0 on the top of a 90gm jig on 1.5 inches of spectra braid. When they get dull change for new, do not resharpen.
I use 5 yards of florocarbon 15-30lb leader, tie good knots because their jag,jag,jag fight is very testing on all connections.
Tip:-if you have a good carbon jig rod, you can sometimes feel the fish pulling gently on the jig if you work it very slowly - just add a single tail hook (2/0 for a 90gm) and you'll get-em!.
They fight from bottom to surface, great sport and great eating, what could be better?
Tightlines.

Awesome info Mick, Cheers for the post!!