Tony: You have brought up a subject that is a can of worms. Balancing props is a must. Not all props may need balancing, but is important to check. There are a lot of products on the market that do a great job of showing if the prop is balanced, but there is a great deal of argument on where to remove material from a prop which by the way is a rotating airfoil. As a retired aircraft mechanic from Horizon Airlines in Portland, Oregon, we never removed any material from the front face of a prop. You will find a discussion by many that I am full of B.S., but the fact remains that the shape of the front of the prop is designed to develope the lift(forward thrust) and not the back of the prop. I expect a lot of poison arrows to be flying my way for saying this, but dig deep in aeronautical engineering and the truth will come out. I suspect the best way to balance a prop is to add some white, or yellow paint to the tips in an amount that brings the prop into balance. This will also give you a visual idea where the prop circle is when the engine is running. I have been told that the only props in the market place are the Bolly line from Australia which are sold by Dar Zeelon, and others.
Whoever answers your question, will no doubt give you a thread or two to read about the subject. Just keep in mind that the prop is shaped just like the wing on your model. I hope my info helps you with your flying.

Rich S.