The cheap stuff is more likely to fall to bits tbh.

I used Thermo Tec wrap to do the manifold on a car.

http://cgi.ebay.co.uk/Performance-Ex...QQcmdZViewItem

Much more pricey but my mate uses it on his 800hp corvette and so far its not fallen to pieces like others I have seen.

If you look under exhaust wrap on ebay you will also find the metal ties which work very well.

When fitting it you need to make it nice and damp (I soaked it) then apply it nice and tight.

Warning though, it will feel like you have just slept with a community of fleas if you dont wear some sort of gloves