Re-build totally (rip everything out ans start from bare hull), or convert only?
One way or the other you're going to have to foam fill it or you won't be allowed on any waters.
I know 2 guys who have totally rebuilt boats and I know of guys who have done conversions (just adding carpetted planks and fit livewells etc.).
There are also boat building forums which you can log onto and see what they did.
Google BOAT BUILDING FORUM and see what comes up.
PM me