I'm still in the dream stage, and I've purchased nothing. Realizing the engine is just as important as the airframe, I've found an interesting option. Superior Air Parts in Coppell, Texas has a build school. You can build a new engine under their supervision, or you can watch while they build it for you. I haven't called about availability or pricing because I have concern about the size. Their smallest is the XP-320 (cubic inches), 160 horse power, at 290 pounds overall weight. I haven't found a definitive limit, but the Kitfox website mentions projects built with all types of engines 150 hp or less. So......., is this engine even feasible? Thanks for your input.