What engine do you have?
Amel sold many SMS with AutoProp’s. They are an excellent choice. These props automatically find their pitch depending on conditions (speed and power applied), with lower pitch when you are motoring at higher rpm, slower speed, and higher pitch at relatively lower rpm and higher speed.
MaxProp also works well on my SM.
I repowered with a 110HP Yanmar when my 78HP Volvo died, I still have the old AutoProp and can sell it at a significant discount if you are interested.
St Michaels MD USA