What a dream project you are doing!!! Congratulations and good luck, now for my 2 cents worth... Wrapping the headers will do a tremendous amount to control the heat and help protect the surrounding items. I had to do this on a drag race car w/ a very long set of Hooker headers to keep from melting a fiberglass hood. The difference was amazing! Obviously on turbos is to get the heat to them, and any lost is a loss of H.P. You can obtain this product form
www.summitracing.com and I know they ship overseas. I would even consider double wrapping them in your situation. The only thing not to do is ever try to pressure wash it, as it will blow apart. Good luck!!! Craig