I found a local Powder Coat place called Finishing Touch near the airport in Monterey. I took the car in yesterday morning and John, the owner, had it done this evening and it looks fantastic. I left the car with him; he took the wheels off, took them to a garage he uses to have the tires removed, prepped the wheels, powder coated them, took them back to the garage to have them remounted and balanced, then put them back on the Z.
He showed me a bunch of color samples and I went with this very dark gun metal that looks black in the shadows and has a low sheen... I really like the look, what do you think?
And, thanks everyone for the feedback and advice.