http://www.bellis.com.au/ is a Brisbane based company, but they make and sell more types of heatshielding than you would have thought possible. I'm sure there are some Vic based companies that could supply what you need.
Bernie - Scott and I wrestled with those pipes when we wrapped them. We did it without wetting them, and wrapped each pipe individually. It made things VERY tight when all the pipes were squeezed into the collector - so much so that we had to trim some header wrap to allow certain pipes to join together. All worked out pretty well in the end. I bought a 50m roll from Bellis, and we just kept winding the main roll around the pipes. No wasteage that way. We needed all 50m !