Depending on the type, probably more than enough unless you want it to try to plane. A 5 pole 385 rated for 15 volts but run on between 6 and 8 cells will be plenty. Direct drive to a three blad prop about 35mm, which is not critical, buit is the size as supplied, and available from most model shops. Just dont gunge the prop shaft tube with heavy grease.
If you use "D" size cells, you won't need as much ballest.
