TimBle,

I am using the ST .10 motor, available from Tower for < $25. Its rated at 1250KV and over 300 watts. With a GWS 9x5x3 (three blade prop) I can get it off the water in about 15 feet, but you do need to cut off the existing motor mount, then add a spacer, to make it work. You might want to move the CG back to get a better roll rate, I typically fly mine at 31 mm and others have moved it back to the spar to achieve more control response.

Bob