HMM three blades are better than two eh. Someone should have told this fellow before he set a world FAI speed record few year back with a single blade.
One thing for sure when thinking three blade, and that is you better be darn sure that the is every conceivable selection you may want to try is in fact actually available lest you may have to learn how to start carving them. Selection is pitifully poor when compared to two blade.
Another thing to remember since scale fidelity seems to be an issue and that is simply for many of our airplanes an efficient three or four blade prop for most engines is in fact tiny not only in diameter but blade planform and this typically looks downright silly. A reasonable two blade actually looks far better for many models. Its precisely for this reason that most scale rules allow a flight prop and for static scale judging a non flight prop.
John