So many choices, it staggers the mind. I've had plenty of .40 siz planes that have flown well with a .40 engine (usually OS .40 FP). I think a lot depends on what youi want to do - slow flying, get a .40 Size Cub, faster get a profile kit, just having fun a 4-Star Forty. I really don't know what to tell you on what kit to get. You can always try a SPAD plane.