Thanks everyone. I think that I'll stay with the OS. Someone told me that the Saito has a tendency to vibrate.
It looks like I will have a choice of props to use.
Suggested Prop(s): Stunt planes: 11x11-12, 12x10-12, 13x9
Scale models: 13.5x8, 14x7, 15x6, 16x6, (12x8 & 12.5x7-3 blade)
To tune the engine down, which prop listed will give the least performance?