Radio: a FRS Motorola will do you just fine to start, there cheap and sold everywhere and once you get a feel for what your needs are you can stepup to something better.
Headset: Me myself Im looking at getting this one to use with my Motorola.
http://ebaybanned.com/product_info.p...oducts_id=1787
AirsoftGun: Go for something with a ver.3 mechbox in it.