Man I wish that I could hear the end result!
When I did my last car I used Dynamat Extreme bulk kits. Buying them on eBay, Amazon, etc I saved quite a bit. Good thing since I used a lot of it. Did every inch of the interior, roof, inner and outer doors, etc. I'm sure there are cheaper alternatives.
If you don't have a roller, I suggest picking one up. They make it easier to get it completely down quickly.