Any good interior place should help you out. They will have numerous types of materials to choose from. There is a place in my town that does window tinting and custom fabrications. They sell vinyl, leather, cloth. Just about everything you can think of. They were very helpful with answering my questions. I would stop in and find someone will to help out.
Doing the door inserts are pretty easy. They are just a glue and stick then work out the bubbles. Parts like the seats are quite a bit harder. I don't know if you want to go that far or you just plan on doing the door inserts but here are some pics.
First take the door panels off.
Steps for door removal
Here you can see the clips that hold the inserts in place.
This is how you get the rear panels off
Remove the rear panel
This is the rear panel removed.
and you can see the rear panel clips that hold it in place.
and the rear panel removed.
Taking the carpet off is pretty simple. You just rip it off. Then you need to go over the surface to make it smooth. Any little bumps and imperfections will show through the smooth vinyl and could possibly tear it. Just make sure it is smooth. Going over it with a rough grit sand paper wouldn't be a bad idea. People here have used a 3M adhesive spray. I would suggest spraying the insert and the back of the vinyl so you have glue to glue contact. Then just put the vinyl in place after the glue is real stick to the touch. Rub into place and work out the bubbles. Wrap the edges and secure the back.
Here is another thread where Ken did the vinyl wrap.
Vinyl wrapped inserts
Hope this helps a little. Feel free to ask any questions and I will try to help.