Black Rustoleum BBQ paint works good if you prep the headers good... knock off rust and scratch them up with scotchbrite or a wire wheel... it can last for a little while. It's a good, "Fuck, I'm going to the river this weekend and my headers look like shit!" sort of move... but to make them super nice and have it last...
X2 on Embiee! They did a great job on the headers I've sent and it seems to last much better and stay nicer than local guys that "do ceramic coating". Plus Jeff is a boating guy... so it's cool to keep loot/business in the community.