Here's some of the vendors I buy from, and why I like them. I'm not getting anything from them because of this page / am not sponsored in any way.
Has most items you need. Flat shipping, no matter how much you get. Sends stuff in 20 different boxes. Doesn't require a medical license for anything.
Also has a wide selection of items. Has needles and BD syringes for a good price, if you're stocking up on HRT supplies as well. Requires a medical license for some select items, but it's not a problem for us. Cheap shipping. Does not ship partial orders, so there can be unexpected delays.