I sent some BMW motorcycle pipes to Jet Hot one time, they held up perfect, never did peal or discolor, coated inside and out. I was thinking of sending headers off my bird when I remove motor.
Normally you can find a local guy to do it for about the same as Jet hot. I paid $225 for my headers and $150 for the intake manifold. Just look up local powder coaters and give them a call. The guy who did mine offers a lifetime warrenty against cracking on new headers and a 5 year warranty on used.