Well, the thing about lighting is that there is no right way and no wrong way. There are a myriad of choices and each have their pros and cons.
What I tell people is to do their research, talk to a lot of people, and WEIGH what they SEIGH
oh man I'm funny sometimes...
Anyhoo, as far as halide goes, remember that the longer your tank is, the more of them you need because you want nice even lighting as it looks nice. You also do not want to place halide over a center brace or the euro-brace of an acrylic tank, the intense heat may melt them.
I firmly contend that halides are cheaper in the long run to operate than a comparably intense PC, VHO, etc because the bulbs have to be replaced less often, and they are far more efficient than even the most efficient fluorescent. If anyone disagrees with me, they are wrong.
... man i'm on a roll ...
The rule of thumb that I have heard and happen to agree with is that one bulb every 24" of tank width is optimal. You can also try less halides and be creative with placement, but ask yourself if you want to be limited in your aquascaping options, because flow is always erratic, so you are often trying to find a good spot for flow AND light in that situation. It gets worse when you deal with anemones, because they can move around on you if they don't like where they are, and if they pick a dark spot, it can be fatal for them. You need at least two, and if you skip a third, you need supplemental VHO or PC to fill in the gap, and that'll run you near what a third halide will cost. If you are trying to get great lighting on a budget, I'd still stick with what I said above... use 14K. That will run on it's own without supplemental fluorescent, so you save money on that.
From there, it's just a matter of wattage, and that's where you have to strike a balance. 24" is a lot of depth, so if you are ever planning to put clams or other light lovers on the sand, you need at least 250 watt bulbs to maintain intensity at that water depth, or even 400 watt. At the same time, the bigger bulbs you get, the more energy costs and the more water heating (and possibly a dreaded chiller purchase) you'll get.
Like I said, it's a matter of personal choice. If I were you, I'd ask as many people as possible who AREN'T TRYING TO SELL EQUIPMENT. Gather up all the opinions and combine it with some solid reasearch from books, magazines, etc and decide on what you want.
