The G45 will fly a 20lb T28 no problem with authority. The G62 will fly most warbirds up to 32 lbs or more comfortably.
You can purchase the G45 or G62 at either Horizon Hobbies or Chief Aircraft. Chief aircraft has the better price. There are probably other sources as well.
http://www.chiefaircraft.com/rcmsec/...enoah.html#g45
http://searchrc.horizonhobby.com/ind...d=12E7DB77D75C