Mike,
MDF or Multiple Density Fiberboard, is just that, fiberboard, no wood. Reason behind this is plywood has hollow voids inside the plys. These voids will cause rattles and vibrations, if not careful. I am from the old school too, being a Carpenter like you, and love wood. Can't even stand the thought of using particle board. I built my speaker box out of BC grade plywood.
Never having any real subs before, or real hard hitting subs in my truck, I thought (this was the first thing I did wrong, think), plywood would be fine. I wish now I would have went with MDF, but my box is fine, so far. The MDF will only let you hear the music, not the plywood trying to make music.
Hey, I know where you can put your amps. Build a center console and stick them under it. I remember someone around here doing just that.
I am like Eddie, well not really like him because who would want to be like him,
, but anyway, I like to drive up close to the wheel. I have times when my old back acts up. Sitting up close sure does take the stress off the back muscles.
With these trucks, if you have anything at all behind the seat, you are under the wheel. It sure would have helped if they would have made them a couple inches longer.