Excellent post, you must be burning the midnight oil.
I have done a little research on sound proofing and heat insullation and there are a lot of products out there to chose from.
I found a couple of Aussie made products from a company Thermotec suited our project needs. There is a bit more info lower on the page in the link below.
http://www.aulro.com/afvb/projects-t...project-9.html
Thanks for sharing your project,
Erich

