Marrk - the 91 with a 15x4W should be ok ... slightly nose heavy but not too much I think. She flies better than the F40, more versatile for sure as its a big 40 sized plane. I would not go with the 3001, you will need a bit more torque and also you do not want take the risk of the plastic gears stripping if you fly her slightly hard. I used JR539s on 6V and that was ok.