I am on the same boat. I found one that seems legit
FURBALL CRITTERS, Non-Biting Hamsters & Rats| Santa Cruz, CA
She sells stocks to some stores so i am not sure. One of the stores I know
(a independent one) well, they have an excellent reputation, their cages are always clean, the animals have a variety of food etc. When you go there there are always employees that are super knowledgeable of their animals. So I am thinking she is ok.
I hope she is not a hamster mill because she has a female long hair Syrian that I really want and she is 1 1/2 from my house.