Help selecting a planing hull

I would like to purchase a hull appropriate for my next project, since I have finally now been given a "round tuit". Having no experience with planing hulls, I am asking for advice in selecting the most appropriate hull for a new power plant I am building. I want to go as fast as is reasonably attainable, with a monohull, and not a hydroplane.

A statement of requirements and criteria:

Boat length 15 to 20 feet, running in protected waters.
Power plant, fuel, and passenger weight, about 800 pounds total, inboard engine plant.
Engine , 15 horsepower (11.75 kW) RPM is between 1000 and 2000, if higher RPM is required, then step-up gearing would be required, possible but to be avoided if practical.

I have a 14 foot O'day sailboat hull, and I cut the centerboard out and installed a one inch shaft, driving a 14 x17 prop with an electric motor at 400 RPM. That boat gave good cruising service for several years, and as an experiment I installed a cheap gasoline engine rated at 13 horsepower, and it made 15 statute MPH. I am thinking of something similar, but with a more appropriate hull form for better speed. Hopefully something I can pick up used on e-bay or ?? for a small cost. If necessary I could build a hull in plywood, but if I can buy something appropriate the costs would be much lower.

Thanks in advance for advice from the knowledgeable people here.

 

If you want the most speed for the power, a jon boat will probably work fine in protected waters. You can find them used for not too much money.