I recently had a Panda generator installed in the aft lazarette of our Catalina 400. While I'm very pleased with its performance, I would like to add some soundproofing. I'll probably build box around the cover with cutouts for the air intake, hoses, etc as well as adding a layer to the wall between the lazarette and the aft cabin. Can anyone recommend a brand of soundproofing board for such a project? Thanks in advance.