Do you not have a local fabric store of a good size? I know how frustrating it can be looking for just
the right trim (I used to be into fantasy costuming some years back.) I've also occasionally gone to a thrift store and lucked up on old prom dresses or suchlike that may not be in the best of shape but have the trim I can salvage.
eBay is always good
If you want plain braid you might do a search for "soutache" which is another term for the just plain metallic ribbon.
Also I'm not sure what all's here, but I did a search for "costume supplies" and came up with this site:http://www.milieux.com/costume/websource1.html
I'd be surprised if some
body didn't have a good selection of braid and trim. Fantasy costumers especially are quite fond of "sparklies"