I always seem to lean toward bouncy seat frames as a start. They are still out there if you keep looking around.

It would be nice to have seats with more support, but as said above, the stock seats aren't bad if they're in decent shape.

The aftermarket carpet I bought off Ebay was all right, but it doesn't fit quite right in the cargo area and is a bear to install in the front. It really quiets the inside down compared to running without it, or having a bed liner coating, I would imagine. If you carpet the cargo area, put some kind of extra padding under the carpet so it won't kill your knees if you end up crawling in the back for things.

Stereos are pretty easy. In dash units are so cheap, it's hard to make an excuse to keep the stock one or go without. The doors accept speakers, but you may have to cut metal, as they are a funny size. I've used both 5 1/4 and 6 1/2. Aim for ones with a thin profile, though, as the windows may hit the magnet if they're too deep. Mid-panel, again, the stock mounting is for a goofy size. I found the later Gen 1 models' "boxes" that extend out from the wall of the truck to be quite useful. 6 1/2" fits great, and you reuse the factory grills, so they look stock. You need to trim the plastic side panels to fit back around them, though.

The in-dash speakers are suitable for a CB or something. I think you can squeeze a 3 1/2" in there in the really small Gen 1 spaces.

Mostly, these trucks cry out for cup holders and armrests. Who's got the easy hook-up on them?

John B.