Foster&Smith, Marinedepot, Aquariumguys, are all legit. Both Foster&Smith and Marinedepot also have great phone service when you need it (I've never tried aquariumguys by phone so I can't comment). The only thing I would look at are the terms & conditions. Foster&Smith is superb about returns and credits (not incl. s&h). All 3 delivered on time, intact, and without errors each time I've used them (the same can also be said for PetSmart when I did find a good online price from them).