sboice,
What are you looking at keeping in the tank?
With all due respect to those who will tell you you have only one or the other option, without knowledge of your goals for the tank, it is hard to say what you will require for lighting.
Since you stipulate that you cannot go MH, you will probably not be able to keep SPS very well. Soft corals, on the other hand are another story. You might look at the lengths of some of the power compact lights and sort of draw a diagram of what ones you could fit where based on their sizes. (Don't forget a place to get your hands into the tenk!)
You can probably keep a really nice soft coral or semi-reef tank with power compacts. If you are looking at a fish only or fish only with live rock for atmosphere/filtration you can probably do quite well with normal or high output flourescents.
Decide what you really want to keep, and base your lighting on that. You will probably be very unhappy if what you can keep is determined by your lighting rather than the other way around.