I have a fourstar 60, and had an OS .91 and a Saito GK 100 on it. Both flew the plane very well. The vertical was not "unlimited" but, it got it as high as I wanted it, very easily. As the others have said, it depends on how much money you want to spend. If that is not a concern, I would strongly recommend the Saito Golden Knight. The only thing that looks better on the front of an airplane is a multi-cylinder! And the sound is GREAT.