This picture is the covered bow of my boat. It's not going as far back as the one you've got, but the age of the boat is the same (old) and what you're describing sounds to me like cutting the bow back to something like what I've got. I'm clearly biased, but I think you can do this up really well. Another thing in your favor is that the cruising style boat you're looking at is usually better built than the plain utility V's, rated for higher hp, and maybe starts with a flat floor inside?