RE: stainless or copper
About 10% of my props are SS. I'm a fan of the Prather props and have many from the 41mm 215 to the 78mm 280 all in SS.
I'd say the biggest advantage I find is it holds sharp edges a lot longer. Being a harder material it is a lot more time consuming balancing and sharpening the props. A nicely done up SS prop looks great on any hull!
Ryan