OK, I think I'm getting warmer I'm thinking 6" by 2' would be enough to cover both turbos...
http://stores.shamrockperformance.com/Detail.bok?no=92
Consensus on the other forums is that it won't cause premature failure of the turbos. 32 bucks sounds like a reasonable price.

 

It was from titan, you'd have to give them a call. I think the brand was cusco or something.