I think they would look very nice in gunmetal. Since they are off, why not hit them with a spray bomb and give 'em a look. If you like it I would check into a powder coat for them.
That said, there is a "chrome" powder coat you might check into. I've seen wheels that were done with this and unless you looked very close you would not know it wasn't a real chrome finish.
For re-chrome have you checked with Tri-state? Not cheap, but I can vouch for the quality of their work.
C