imho, lighting choice will be decided by what type of corals you would want to keep. for soft corals, you only need maybe 2-4 t5's. for sps's, anemone's and such, more t-5's or dual mh setup would be required. between a retro and fixture, i tend to lean towards the retro as you can install it yourself, configure it to your canopy or build a canopy yourself to suit the retro. the fixture is a bit more expensive but you get the lights in one sleek, clean package. my suggestion, decide on what you want to keep, leave room for upgrade so that in case you decide to keep light lovers, it's simple to add more bulbs, or incorporate a mh setup or two. hth.