Ive had great experiences with liveaquaria.com. reasonable prices on delivery, incredible job packaging the fish for transport.
Thewetspot is decent but their packaging left a lot to be desired. That being said all my fish made the 3 day trip alive.
I usually dont give bad reviews online but i will advise to avoid bluegrassaquatics. Bad customer service, some fish dead on arrival, shoddy packaging.
Ive heard great things about aqua-imports.