a lot of us who order from Rio do so because Stuller will not sell
to "non-professionals". I suspect the professionals have already
done as you suggest; but what do the rest of us do?
Call Santa Fe Jeweler’s Supply at 1-800-659-3835
(http://www.sfjssantafe.com/) and get their catalog. It’s nowhere
near as comprehensive as Rio’s set of catalogs but you’ll get a real,
and real knowledgeable person every time you call. And every time I
make an order, there’s a handwritten, signed thank you note and a
couple pieces of candy in the package. There really are lots of
other suppliers out there for hobbyists and professionals alike, but
Rio has for years seemed to dominate the industry.