Assuming that the statement “just bought plans” is correct and the mostly finished hull photo isn’t yours, I’d see if they will let you exchange the plans for their 14’ model, as I think you’ll be much happier with it.
Unless you live on a canal and have to literally carry the boat onto a back porch, a 14’ boat is so much more versatile. Any 12’ skiff is basically a kayak and you’ll never be able to take somebody with you safely, unless it’s on a pond.
Even if you want to fish solo 100% of the time, a 14’ boat will generally float shallower, pole better, allow you to carry camping gear more easily, simplify rod storage, etc.
The other issue with the 5-6hp motors is they are on the ragged edge of being able to plane with 1 person and an extremely light load. It’s not a question of being able to run 25 mph instead of 20 mph, it’s coming out of a creek you’ve been fishing and having to cross a section of open water to get back to the ramp. Once the wind has picked up and it’s choppy, it can be dangerous not being able to get up on plane and just having to suffer the waves rolling into you.