I was reading around on the internet and apparently BBQ paint is a cheap way to protect those headers. Other high temperature paints don't work as well as they should. There is a professional ceramic painting technique, but can't be done at home, and the likely hood is that most companies in China will be as bad or worse than Jianshe Yamaha.
Krylon is the brand name to remember. I think one of your colleagues is visiting the USA and could bring you back some!
http://krylon.com/products/bbq_stove_paints/