I have seen a few copper and brass cantle sporrans and think that most of them look great. They are harder to find then the grey/silver color metal cantle sporrans yet they are out there. Artificer has made some and some and on rear occasions vintage brass cantle sporrans have been spotted in places like ebay. On a quick search I have found the following:

http://www.kilts-n-stuff.com/clearan...e-sporran.html
https://www.scottishtradingcompany.c...products_id=47
http://www.freedomkilts.com/product/...-brass-cantle/
https://www.tartanista.co.uk/tartani...e-v-12317.html
http://store.stillwaterkilts.com/Bro...Belt_p_61.html

The prices are all over the place.

If you want one sporran that will work for most occasions a hunting sporran with a metal cantle is one sporran that can do this.