Do you want precut, or are you doing a custom number? If you are gonna cut and fit it yourself, go to home depot or lowes and check out their rolles of indoor/outdoor carpeting. Buy just as much as you need and you can get it in all kinds of colors and several different textures/piles. Before you put it in the truck, scotch guard the h-ll out of it, then all stains will come ut with hand held upholstry steam cleaner thing. I got mine for $79 and it works great.
All the same, I would just bedline the whole thing.
