A good place to start off in combat for youngsters is with a Black Hawk Models 1/2a combat wing. It is CHEAP (2 for $14.00) Quick and easy to build, easy to repair and fun to fly. WWW.BLACKHAWKMODELS.COM (UNDER PS MODELS ON THE CATALOG PAGE)
Larry

Try the Li'l Hacker from The Core House for a great Half A combat wing that can take you from basic flight training through combat.  Basic training with any reed valve engine on 35 ft lines.  Full blown combat on 42 ft lines with  a larger engine such as the NV 049 or 061 Big Mig.

http://home.earthlink.net/~philcartier