RE: Prop for Ducted Fan Engine
Aloha! 25K is not realistic but you could get some real good speed numbers from a DF engine propped correctly. In the fan units they seem to turn 19K-22K on a prop it is obviously much lower.
I would recommend the Hurricane over the Byron if you are going to modify an Enforcer. Hurricane is under new ownership and the performance is FAR better than the old Byro stuff. See pics below for example. Byron, then Hurricane front then back-