if you get one with a gold, black or chrome finish you can always spend a bit of time removing the plating and re-buffing it. Most plating will come of quite quickly with fine sandpaper
Its not the ideal solution but if it gets you where you wanna go its worth it.
Alternatively i have heard nothing but good things for this company:
http://www.ets-hardware.com/They custom make bridges in a range of colour options - i am sure solid brass with no plating would not be an issue for them if you asked
The ETS GB 7000 looks pretty smart.
Cant promise that will be cheap though