Midnight,
Prop balancing is importaqnt, especially at high RPMs. If you have an improperly balanced prop it can cause vibration that is very bad for engine and airframe. You can get several prop balancers, check at your LHS or at www.towerhobbies.com.

3 bladed props are less efficient than a 2 bladed prop. Keep that in mind if you decide to go with one.