Liveaquaria is fantastic in my opinion, but be aware of what they are. Their main site is simply a way for you to order fish directly from a wholesaler. A Liveaquaria employee goes to the wholesalter, packages your fish, and ships it in a LA box. These fish will have undergone no observation and no treatments. They are also going to ship in water with a salinity around 1.015. I highly recommend having a QT system set up both to watch and treat for illness and to have a chance to slowly raise salinity.
They also have a Divers Den section which are fish actually in their care that they have performed fairly decent observation and treatment. Its not perfect, but you are much more likely to get healthier fish.
Customer service is absolutely top notch.