The line of Testor Metalizer creates a good metal finish. Also, there's a product called Alclad II, and it's an airbrush ready metal paint, and supposed to give a realistic metal look. I'm satisfied with Metalizer, but can't comment on Alclad because I haven't used it yet.
Also, there is a product called Kosutte Gin-san,
http://www.hlj.com/cgi-local/hljpage.cgi?WRK00251
and this gives you an incredible sheen beyond belief.
I asked Chrome Tech USA to chrome some parts, and I'm a satisfied customer.