If you are taking the time to get a custom frame that will last a lifetime, give it a coating that will last a lifetime, look into powdercoating! It will last forever, never chip off, and prevent rust better than paint will. Good coaters like http://www.spectrumpowderworks.com can even do multi-tone, metallics, fades, clearcoats, etc.

peace,
sam

P.S. I vote for polished and clearcoated.