i used to use T5's and loved it, went to LED's and it was ok, and now i am back to t5's for a while, you can definitely keep SPS, clams, basically whatever. There are may bulb combinations you can do, my new bulb line up is the following, and they are on a 24" Sundial fixture.
ATI Purple Plus
ATI Blue Plus
ATI True Actinic
UVL Aquasun