I have one on my Magic with a 12x4 power point(wood) this gives me about 16000rpm on the ground with a mac header and tuned pipe. I kind of depends on what you are wanting to do other than hover and what plane. I like the wood props because they seem to rev up quicker and if you dump it in a low hover and hit the prop it will break it and not the firewall!!!!!!!
On mine the 12x4 hovers a little easyer but, put an 11x4 and it will loop almost a fast as a boom plane!