If the tank is 24" or deeper I would stay away from T-5 lighting if your intention is to keep what every you want. If you are going to limit yourself to softies, lps and possibly a bubble tip anem the T-5's will be fine, SPS would have to be up high and so would clams. I personally love T-5 lighting but they have there limitations, IMO. If you are going to go the t5 route I would say no less than a 6 bulb fixture. And definatly individually reflected...
If your using a canopy and decide on MH lights make preparations for ventilation. They get very hot and if not properly ventilated will increase your tanks temp to dangerous levels. Most people accomplish this with a few hang on fans but others have found it necessary to buy a chiller. As far as appearance, T5 lighting is much brighter than MH but, MH IMO looks much more natural. Another thing I noticed too and I dont know why but for me when I had t-5's on my tank I had nasty algea issues. Since I switched to MH, no more algae.... I dont know if its a by product of the flourescent light or not but its what happened to me. HTH.
