Jimboat

looks like a fun project. you should decide on hull type, size, weight, target velocity, etc before considering engine spec.

If you don't have a lot of money, a used boat is a better idea. You can't choose a power source until there is a hull to go with it...

There's more to making a pontoon boat go fast than a vee or tunnel, but here's some info that might be interesting or helpful.

John, thanks for your feedback. I agree with your comments. While the performance powerboat community seems to use "lateral stability"...