There is a post on this site somewhere showing a 20' that was cut down like you are thinking of doing. The owner is in the Homestead FL area. I saw the boat in person around 6 years ago. I thought it was a cool looking conversion and I'd like to have one myself.

I have pictures of it but I think they are on a old computer that has a issues. I'll see if I can dig them up.

Also try searching this site. I posted about it back then too.