63 Chevy II Wagon

I recently bought a 1963 Chevy II Wagon I plan to use for my mobile detailing rig and in the stages of paint and body work as well as getting the interior materials together that I will need (planning stages of interior). I plan to go with an original Fawn color on the interior but want to make my own door panels, kick panels and back compartment panels).
Anyways, my question for you guys is what should I use for my backing panel for the vinyl? I hear some use original material while others use PVC.
The plastic IMO would hold up best against water, moisture, mold, etc and not warp. The panels are very easy since there are no arm rests (I may make some) and only two small holes for the door handle and window crank. The panel is square and no bends or crazy shapes. I plan to put a thin layer of foam over whatever I use as a backing so I can make a small simple design in it and also have a thicker panel instead of flat vinyl.
Thanks a lot for any information!

I normally use 1/8" luan sheeting for my panels (sub flooring), but it's getting harder and harder to find. My local lumbar yards don't carry it any more. So I recently bought a shipment of PVC panel board (1/8"). I've used it before, handles staples nicely, bendable with heat, but you do have to be careful not to snap off chunks as you're working with it.

You can also use paneling for your backing material. I've done that a lot. It's a bit thinner than the luan, but still works well.

Thanks a lot for the information! Any idea where I can buy Jute matting for insulation for cheap? I want to buy bulk instead of a 4X6 foot piece for $30 bucks. I have 3 or 4 hot rods to do so buying in bulk for cheap would be great!
Also, for sound, do you guys prefer 3M Q pads? I see a lot of guys using the Roofing Peel & Stick from Home Depot and Lowes. Not sure about it since it's not fire proof and it's pretty much tar. I used it before but I have heard some people say not to use it and then I see lots of people saying it is fine. What is your oppinion on this?
Thanks again!

I'm a professional shop, so I purchase my jute, etc. from a wholesale supplier. Some of them (Miami Corp in Cincinnati) also sells retail to non-businesses. Buying in bulk will always be cheaper than small purchase sizes. Not that it's recommended, but I have had cars come through that previous interior work used carpet padding for the backing.

As for the sound deadener, there's another product call Fat Mat (http://www.fatmat.com/) that is similar to DynaMat, but cheaper. I had a Corvair through the shop a few months ago that was completely covered inside with the Fat Mat. The owner said it was half the cost or more of DynaMat, so it was reasonable to use it for covering. And remember that you don't need to have the deadener in every square inch of an interior. Just centered on large flat panels will absorb the vibration and stop the rattling (if you ever notice the inside of an older car's door, it's just a 12x12 square in the center of the door that's used). I've never personally tried the roof squares, but tar pads is what's used stock up in ceilings and other areas of a car out of the factory. Just don't wrap it around your muffler or other combustible spot and I don't see why it wouldn't work (if the floor of your car is burning, then the rest of it is toast and it doesn't matter how fireproof the tar pad is.)

Post some pics. Chevy IIs in any configuration are pretty cool.

I will try to get some pictures loaded onto the computer within a week or two. The seats and headliner are like brand new. Just needs carpet, panels and door panels really.