I realize the consensus on here is that the show Tanked sucks, but I'd still go to their office if I were visiting. I think it's only a couple miles off the strip.
I really need to check this more often.... However yes, the show sucks butt. Personally that is. What they do with tossing fish into non-established tanks, and their attitude towards their customers after they are paid, is attrocious.
However, the stores here in the valley differ based on what you're looking for. Here is a map that we built a while back, of the fish stores here in the Valley.
I'm really sorry for not getting back to you sooner. I'm terrible at monitoring forums. However, I am going to be checking it more frequently and trying to be more active here. If you ever come back to vegas, or plan to, let me know. I'll try to make sure that you get a tour around a couple of the aquariums. Silverton, Shark Reef, Seaquest to name the main ones.