4 blade prop??

[Gfunk]

I have a 150 Optimax, 25" shaft with a 19" pitch stainless prop on my 20" transom V. I bought the TH Marine jack plate to get me 5" of lift and 4" of offset from the transom, just haven't had the time to install it yet..... currently, I'm getting between 5000 and 5100 rpms, with a speed of about 34-36 mph with 2 adults and 1 11 year old on board.
My question has to do with this, I'm pretty sure I'll have to lower the pitch of my prop even after I move the engine back, was thinking to a 17", was going to get an aluminum 3-blade, but I found a 14 1/2"x17" diameter 4-blade stainless prop I can get for the price of a new aluminum 3-blade. Does anyone have any feedback on these types of props on our boats, or any feedback on the pitch/diameter once I move the engine back/up?

THanks in advance!
Gfunk