You could try Johnson's Power Coating in Burlington, right off 295. I've had valve covers done, my intake done and my headers re-coated. The valve covers and intake were excellent, the recoat on the headers didn't last as long as I would have hoped.
Here's a link to my valve covers and intake:
http://www.johnsonspowdercoating.com...mavc-1_jpg.htm
The pic doesn't do them justice. I brought them a can of the paint I used for the block and they matched it for the valve covers (lots of different flavors of "chevy" orange), The raised CHEVROLET lettering is still the raw machined finish, just powder coated clear. These were done 5+ years ago, before they got affiliated with OCC. Hopefully, that hasn't pollluted their way of doing business or the quality of their work.