If you use any type of flourescents, you have to maintain a very SHALLOW canopy and it will not actually be all that efficient. Remember, the most useable lumens per watt for vegging does come from a MH light. That being said, if you have a few bucks to spend, a small T5 fixture is freaking AWESOME for starting seedlings, or even lighting a whole large room that you keep nothing but rooting and rooted clones in. I was running a 24" new wave t5 in a 5x6x6 room as the only light, and using that room only for propagation- it was EXACTLY the correct amount of light in that space. But if you want only a single light, go for the MH. It will actually save electricity in the end.