I would move up to a 21m and with some plate adjustments that boat should be a handful to drive it as fast as it will go.
I was thinking the same thing.. a 21 pitch. I should be able to get close to 60 MPH out of it with that prop and the jackplate.
Right now I top out at about 53.5 MPH. Not bad, but a boat as light as this should be able to hit 60 MPH, in my opinion.