This depends on type of corals. 7300/2, 7400/2 and 6000 Stream are all possibilities and all can be controlled with a single controller but it will depend on whether you do SPS or LPS or softies primarily. For a basic polyps and softy tank I would get the 7300/2 for a mixed tank with lots of LPS I would do the 7400/2 for an SPS intensive tank the 6000.