[McGillicuddy]

I think your planing numbers sound fine. But motor height sounds low. That motor is light by modern standards and is a real nice match for the 20. Definitely raise the motor a notch at least -too bad you can't go more. Get the 13-3/4 by 15 p Quicksilver Black Diamond/Black Max. Quicksilver number is QA2034X. Not sure, but I think Black Max is 48-77342 A45. If your prop is new, see if your prop guy will swap you. Offer him a small token of your esteem like a 20 spot or a case of beer for the guys. Let him keep the hub since you already have one. Take your prop box with if you still have it.

A stainless will typically be harder to turn so you would have to go to a prop of less pitch. Rule of thumb for same prop shape, drop 1"-2" of pitch for stainless.

You definitely want toget as close to that 5500 as possible. Otherwise the motor is bogging and will suffer in the long run. If you cant turn the 15p to at least 5300 you may have to go to the Yamaha semi cleaver series. Probably K (alum I think)or M15 series (SS). They come in stainless too. The Merc product otherwise would be better all around but the semi cleaver might be easier to turn having less blade area, and might get you better top end.

Trim tabs also help every thing.