Best Prop for Yanmar with SD 31 Saildrive?

[quartersplash]

I had a short lived electrolisys problem that ate part of my aluminum propeller on my saildrive. Are aluminum 3 blade props the reccomended prop for this SD31 saildrive and Yanmar 3JH2CE engine combo? If so, does anyone out there have any of these laying around from maybe changing to a folding prop that you want to sell? If this isn't the best fixed prop, what is? And does anyone know what the stock pitch and diameter is?
Gracias

[Badsanta]

I think the prop is more dependant on the size of your boat.

[quartersplash]

Thanks for the tip. I have a 47' catamaran.