I have a Fox 2.4 on my Lanier Edge 1/4 scale with a 73" wing span. This combo gives great vertical and the plane tracks very nice on knife edge. It will also crawl in to land. The gas engine balances very easy by putting the elevator servos in the tail. I am currently running the Menz 18X10 and getting 7700 rpm on the ground but am going to try a 20X8 for more thrust. Try a Fox, you will like it and they are available.