personally I would try and get hold of the reprappertech filaments.

Instead of just adding fairly large metal aprticles to the filament like colorfabb - which you then have to sand, and buff and polish and it's areal pita.

Reprapper tech have used much much finer metal powder and used it as a colourant. So you get filament that looks metallic without any post processing.

That said the unsanded colorfabb filament is pretty cool as uit looks and feels like a roughish ceramic.

I actually prefer the unsanded brionzefill to the sanded bronzefill. Particular for models of statues.