We are flying the world models aircombat series. The Yak 9-d, the spitfire, the p-47 and the zero.

http://www.theworldmodels.com/para/p...?airplaneid=20
http://www.theworldmodels.com/para/p...?airplaneid=21
http://www.theworldmodels.com/para/p...?airplaneid=22
http://www.theworldmodels.com/para/p...?airplaneid=23

These are the specifications

Wing Span : 48 in / 1220 mm
Wing Area : 437sq in / 28.2 sq dm
Flying Weight : 3.0 lbs / 1400 g
Fuselage Length : 41.0 in / 1040 mm
Engine Required : 2-stroke 0.25

So we can't really fly any really heavy engines.