Engineered Applications Inc.
4727 E. 49th St. Vernon, CA 90058
866-637-9211
They do ceramic polished like crackedback's above and black and white. And all optional with that internal thermal coating inside the tubes. IIRC, the internal coating was not that much more.
I very carefully match ported the headers to my exhaust ports before having the headers coated. That way anywhere I cut would be protected by coating it later. Just any little excess just on the flange. With the TTI headers it was very little material. IIRC, half the ports I didn't have to touch.