My choice of Polaroids in conventions would be the electronic flash Pack film Polaroids, the 360, ProPack w/ProFlash, Keystone Everflash, or a modified rollfilm camera (they have X-syncs, even some have PC plugs) or the famous 180/185/190/195, Fuji FP-1 or the Konica version.
If you have a large box a flash bulbs, use the 100, 250 and 350 cameras.
I have pretty much used all of these Polaroids, besides the "Professional" manual models.
You can be like everyone else and use Instax film, like the mini or wide ones, or use the folding sx-70 or SLR 680 using the Impossible Project films.
Here's what I have done with the 100, converted model 800 and a pack film back for my Mamiya RB67.
https://www.flickr.com/photos/cadha13/sets/72157629311629663/
Good luck and have fun shooting.