There is nothing dumber looking on a nice scale ship than a little ol' two blade prop except an even more riduculously small and narrow three or four blade prop. Unless you are going to use any of the old mostly off the market reduction drives you are headed for trouble particularly as you said "making it very scale" read heavy.
Do yourself a favor, make yourself a genuine exact scale static prop. Easy to do with a couple of big wooden clubs and your airplane will never look better. When its time to fly spin on whatever is appropriate.
John