I think the RCV would be fine although I have no experience witht them.

My Ryan us powered by a great running Magnum (ASP) 1.08 with onboard glow. I mounted the engine about 15 degrees off inverted, made a 90 degree elbow and used the stock muffler. It all stayed within the cowl.

The 1.08 provided ample power for any type of flying. Interestingly the Ryan will knife edge better than a lot of 3D airplanes!