Samtec is a large connector company that is reasonably easy to deal with but their website is pretty convoluded. You can try using their build-a-part wizard, but we recommend you get a paper catalog and thumb through. All their literature is beautiful, too bad their website is so difficult to use.
We buy all sorts of sockets and connectors from them.
On an interesting note, they have no stock. They build everything to order! We ordered some parts with an incorrect/old part #. Upon receiving 100 bad connectors, we attempted to return them. The customer service rep just studdered on the phone - they don't do returns! Since they build everything to order, they would have no place to even put returned parts. We were SOL. Kind of a cool business model/concept, but just be sure you've got the right part #.
To help you get the right part # - they'll send you all sorts of free samples! Way to go Samtec!
1-800-SAMTEC-9 (who still does this? I hate it when companies list some horrible spelled phone number so here's the real number)