That part number is for a 14.5 by 19 pitch prop. Are you looking to keep it the same? Change your RPM's at all?
As far as aluminum versus stainless, that all depends on your motor, boat, use, and wallet.
What boat are you running this prop on? What size motor? And what kind of boating are you doing?
Both types have their pros and cons. All depends on what you are trying to accomplish with your new prop.