Welcome to Classic SeaCraft jleek
A single will suit the 23' just perfectly. In todays economy ---------> double trouble, double maintenance, double water pumps, double props etc etc means double expense
I can top out 48 mph with a light load given good sea conditions with my single. The big blocks give you solid torque when needed. How fast do you want to go anyway? How often are you going to be running balls to the walls?
Oh and BTW if you decide on twins, should you drop a motor, you won't plane that hull with one 135hp - 150hp engine......
my 2 cents
Capt Chuck