You might want to check with these guys -- they tend to be competitive on Volvo Penta parts http://www.mcdonnellmarine.com/

As far as mfr recommendations: "Your mileage may vary". They were very wrong when I was prop shopping the last time around -- the makers tables had me way under-propped.

BTW -- no complaints about reverse thrust. I'm sure it's not as good as a fixed or feathering, but it's good enough.