Give these guys a try, minimum buy is enough to do at least 20 pairs of pipes, but is fairly reasonable. They supply most of the leading muffler manufacturers & V8 teams.
http://www.lancastergfa.com.au/index.shtml
http://www.lancastergfa.com.au/acoustic.shtml
The fine stainless wool first wrap stops the E glass from blowing out or melting. the E glass is also a good heat insulator.