I would put something on that will give you about 10 - 11 thousand RPM at full throttle and see if it works out. Then, after flying it, and especially landing it, change the pitch/diameter to meet your needs. Just remember that shallow pitch is like changing gears on a car.. lower gear (lower pitch) less speed, more climbing power and easier landings (slower) and for the tail draggers, this can come in rather handy, if the plane will handle lower speeds. I'm by no means an expert, more of a novice, but that's what I usually do and find that it usually works out ok.