Any 125 gallon setup you see in the stores would be fine, you don't need a predrilled tank, or a t5 lighting just a bar light, go with a good filteration like a fluval fx5.
All aquariums are basicly for fresh water setups, unless they have been upgraded for salt water use. Saltwater tanks are more difficult and more expensive to setup and maintain.
I have found them at Petsmart. Although recently I have had problems finding the filtration for under the rocks instead of the top flow ones. I know that PetSmart used to carry them because I had Pacus (sp?) that were six inches from top to bottom.
