If power, performace and price are factors I think the ZDZ 80 single that I have on mine would be hard to beat. I have an RCS (JMB) in fuselage muffler on mine and the performance at my fat 27# weight is still more than adequate for anything less than all out 3D which this airplane isn't known for anyway. It is whisper quiet with the MSC prop and pulls like a tractor.
My only caution is that RCS seems to be lacking in support lately. Hope they can get their act together before I need another engine cause I base my buying as much on support as performance.