BioMax
+1y
I know that there are a few guys on here that work for AirRide that would probably be able to give you a better idea. But personally, I think that, in order to make the kit easy to install, they use too small of an air bag and in turn it creates a stiff ride. It works out for them because they can claim that their kits handle well, but a stiff spring does that.
As for the rear whell/tire size... I don't know.