Hey Diver. Bracket/outboard is a great option for the I/o conversion on these boats. I seriously doubt you'd be sorry.
Welcome to the site. Is your 9.9 Honda connected to the main fuel tank? What about steering? I have a 9.9 Johnson tiller steer. I just use the big motor as a rudder to steer. In the V-21 I have room in the splashwell for a 6 gallon gas tank and the main motor can still tilt all the way forward.