rear deck panel replacing 6 with 6 x 9

Hi, all My car is a Toyota Corolla '99 Sedan (the rear deck is similar to a camry), and I was wondering how I would go about replacing the factory 6" with Pioneer 6 x 9's. The parts of the rear deck is the car body metal sheet, and over that is a wooden panel(which has been torn...dont ask =P). So im thinking of replacing the wooden panel aswell. 1. What should I replace the wooden panel with? Plywood? Its quite thin, about 7mm.. 2. Do you install the 6 x 9's into the wood, or into the metal sheet under it? 3. I want the maximum bass to come out of these speakers, so what should I look out for? Should I use some dynamat under the wooden panel? Fiberglass the 6 x 9's ontop of the panel? Thanks in advance.