Re: Buildin' a boat
A good place to start is by purchasing some good CAD software meant for designing boats. You can input the dimensions, weight, etc. and the software will tell you about the buoyancy of the boat, how it will ride in the water, and stress areas of the hull. They are tricky to learn how to use, but well worth the trouble in case you build a boat that isn't stable at high speeds.
Easiest thing to do, like mentioned above, is simply stick with another architect's plans, and do some slight modifications if they don't work for you. Even if you can get a boat to sit level in the water on your own, you're going to want to make sure the hull allows more drag behind the center of gravity on plane or else you're going to be prone to chine walking. There's a lot of physics behind building a good hull.
Whatever you do, best of luck to you and hope to hear more about the project.