Myron Toback is a great resource if you need real gold and silver findings, small gift boxes, glues, general jewelry supplies.
You will have to wait a while to be served, and if you're not a regular, one of them may cut in front of you. You have to take a ticket with a number. I strongly suggest, while you're waiting, you take a good look at the supplies, so that when you're number is called, you know exactly what you want. THey don't have a lot of patience, and if you need time to think, they'll move on to the next person.
But, they do have an excellent selection.