custom/aftermarket speaker mounts/panels ??

I've got a 92 Toyota pickup extended cab. As of now, it only has 2 'factory' locations for speakers, and that is sort of below the dash (under driver and passenger heater vents). Anyways, I want to 1) put in some door speakers, and/or 2) put in some rear-cab speakers. In the xtd cab part, there are two storage bins adjacent to each passenger. The 'bins' are about 4" deep, 10" tall, and 6" wide (I might be off with the dimensions, but that will just affect my max-speaker sizes). There are vertical panels that are the 'doors' to these bins. The panels have easy turn knobs, clearly intended for storage use-- I want to turn them into speaker mounts. These locations almost look like they could of been used for a premium sound package from the factory. Has anyone seen what I'm talking about? Are there aftermarket panels/doors that I can just use for speakers? Can someone direct to me a place for custom-fitting fiberglasses boxes/panels to these locations? I have used fiberglass before, and made speaker boxes before, but never fiberglass speaker boxes.ALSO- if anyone has one has 'ideas' for these trucks (where to tuck amps/subs/etc), please feel free to send them along. Any help greatly appreciated!Brad