For the floor, I would see if you can find a replacement/ reproduction carpet mat for the floor. If its too hard to locate one or if you find one but its way too expensive, then you still have another option. And this is probably what I would end up doing. I had a friend with a base model work truck with the rubber mat floor but wanted carpet. But he didn't want to pay over $175 for a new carpet kit. So what he did was buy a roll of cheap carpeting from the auto parts store, and he glued it to the rubber mat with contact cement. When he put it all back in the truck, I was surprised at how nice it turned out. I was making fun of him for trying to use cheap autozone carpet, but it DID look like new factory carpeting. Now I can't say for sure how long it would have held up, but it held up just fine for at least two years, because he sold the truck about two years after putting the carpet in.
I would scrub the factory mat VERY well with Simple green or a similar degreaser or All Purpose Cleaner, and then wipe it completely with Isopropyl Alcohol before spraying the contact cement on it. That will help the glue stick much better.
And you also have the option of searching for a better quality carpet roll than the parts store stuff. I know they sell some pretty durable carpeting for boats. Look around, I bet you can find something nice for what you are willing to spend. The