If nothing else, that may serve to quiet these yahoos down for awhile.
Well this law wouldn't affect that, for that you want a long gun, not a handgun. Preferable an evil assault weapon (or better yet a real assault rifle) OR a "Serious Social Purposes" shotgun.
Unfortunately the former are all but banned in New Jersey. Actually they are subject to the same controls and procedures as machine guns, so if you want one, might as well go for the Real Deal.
OTOH, a nice lever action in 30-30, .44 Magnum or even .45 Long Colt, would serve almost as well. Then again a scoped bolt action hunting rifle, in a serious caliber (meaning .270 or larger) might also have it's uses in such a social event.(98K Mausers and 7.62x54 Moison-Nagant or clones would serve quite nicely too, and they are cheap)