Hmm, it would be difficult to fit a 10", perhaps up higher and coming out more into the trunk space. I chose the driver's side space because it was just dead room, and I still wanted access to the jack on the passenger side. I had an 8" sub in my crewcab and it was plenty for me; I don't do boomy, I like full sound.
As far as schematics, I just taped up the panel, layed two layers of fiber glass and popped it out. Added some more layers, stuck my mdf ring into the bottom area (fit snuggly with a little glue). I then stretched a t-shirt over the part and soaked it with resin, and added more layers. Finally, I spray-glued down two layers of 1/4" foam (it was actually roof liner material I bought at the local fabric store, along with the black leather vinyl). After that, I stretched the vinyl over the foam...wallah!
Thanks guys.