There's loads...are you after plastic or metal? There are some great plastic pre-paints out there from the like of Dragon, Takara & other Japanese firms - as well as kits of course - which vary from the nice-and-simple to the "I can see the pilot's parting"...
Then you've got some nice metal [& resin] ones from Pendraken & Minifigs amongst others...and some people like to use 6mm [or smaller] - (a) because they're cheaper and (b) they look higher up
As for displaying them in-game: it's not essential to have the models at all - but everyone knows you'll do more damage if you've got something to place down [& even more damage if you add sound-effects...]
If I'm using plastics [or 6mm metals] I'll make a stand from a large paperclip; for 10mm metals, most come with a metal flight stand - or there are loads of different ones available; something that can look really cool is to use an old retractable car-radio aerial: cos then you can vary the height!