[tevake]

Ahoy Rooster; I reread your post, and realize that I went off in another direction than you were thinking. Sorry. Your idea of using flat panels is another way to create a new bow shape. You could get sheets of high density foam. It comes in a variety of thickness and density. The way this material gets its strength is by glassing a skin on both sides, producing foam sandwich composite. Once you get panels of sufficient strength they can be cut to size and fitted as you are thinking. I think you would want to glass them in place with a well prepared 2inch or more overlap onto the hull. And glass all seams. I would also plan to build some internal baffles to support the longer sections of the panels from the crushing loads of wave strikes.
I hope this helps
Richard