What corals you plan on keeping will determine the amount of (and therefore the type of) light you go with.
If you only want simple mushrooms and softies ~24" or deeper then T5's will probably be fine. If you want a brighter tank, or wish to keep higher-light requiring corals, then you will need the extra penetrating-power of a 250+watt metal halide or some type of LED fixture.
If interested in LED's, I sell a really nice LED fixture: (55) diodes at 2watts/each, fans, seperate white/blue power-cords, really sharp, crisp light and great penetration. I have (2) of these on a clients 38" deep 160gallon and they are gorgeous. Only $190/each. If interested I can send you more info and specs.