bead board
I am also contemplating the same refit on the M33OI. My oday i just painted the cleaned hull interior as well as the bulkheads with exterior 100% acrylic latex house paint. The interior looks like new.
The usual, and eccepted way of attaching wood to the interior of the hull is to epoxy glue furring strips to the hull using boards to "clamp" the strips to the hull. Then you should glass over the furring strips to assure they won't come loose. Then just apply your bead board like you would a wall in your house. My delema is what material to use. I have been looking at solid wood tongue and groove flooring for this. Just waiting to find a good deal on the price. Good luck, take your time- it will be worth it. I also have heard that you want a small gap between boards-say 1/8 to 1/4 inch between them. This is so they don't creak all the time, because the boat is constantly flexing. Just my 2cents worth. Patrick