I can also vouch for sewezdesigns - I've placed many orders with Sue and her service is impeccible. I'm going to miss her!
Her prices have always been low, and with her current sale of $6.00 for a large spool ... WOW. I ordered a dozen spools this weekend.
I looked at other sites - Sue's prices can't be beat. Sometimes Tristan has good deals as well but only if you buy the combo packs.