I have a Saito 91 in mine. I'm closer to sea level, but it's a blast with throttle management. I only use full throttle when it's pointing straight up. Don't worry about it being nose-heavy. These all come out tail heavy. Mine is at the back of the recommended CG range with the battery at the front of the RC compartment. You may have to put the battery above or below the fuel tank. As far as 2-stroke, I would go with at least an O.S. 50. If you can afford it, go with 4-stroke Saito 72, Saito 91, or YS 63. OS is same performance but a little heavier. The YS with pump would be nice on this plane due to the inverted engine. Non-pumped engines flood easily because the tank is higher than the carb. Do a search on regulators, too. I'm thinking of getting one to help with the flooding problem I have when it's on the ground. I don't seem to have a problem once the engine is running though.