I'm with Anthony (sorry man, I can't call you Seahorse with a straight face
). I say either replace your whole lighting with LED (which you might be able to do for $40 or so... I show you in a minute) and go with halides. With everyone and their dog going to LEDs these days there are some mean deals to be had for halides. A 24" fixture can do a 30" tank, though it'll be a little dim at the edges (PM BlazingArrow to see his wicked 30" tank. He's using my old 24" 150W Coralife fixture) or get a pair of pendants. I bet you could do it for about $100 to $120.
The whole lighting thing is a minor detail. I could tell you how to make a sexy light hanging kit that would attach to your stand for less than $20.
Now... for LEDs. Let me first direct you to exhibit A:
Aquastyles. You could get everything you need for a 24 LED set up for about $85 + shipping.
Exhibit B:
Pinhead's advice on cheap LED builds. I'm going this route for a cheap retrofit myself. The most expensive thing would be the heatsink and you can find some cheap ones if you look around.
HeatsinkUSA is pretty good.