I always said 24G nanocube or aquapod but the bad thing about this systems is light! so if i was you spend your money wisely and get a bowlfront tank, a filter,skimmer and a good combo light with MH & PC convined cause with the lighting of the all in one systems like nanocube or aquapod you'll be able to keep just some few low light corals and not that colorful too will spend less with does systems but in the long run you will spend more so start your own setup.