Hi scuba Chris, and welcome to SWF
You been keeping wet? Is your 30 a standard 30? 30in long? You could do the 150 clamp on or a pendant even and use the standard fluorescent light you have alongside it for actinic supplementing. Actic is a blue light which is used to both make the lighting more pleasing to the eye and give the corals a much prettier color. It's almost like a black light. BUT NOT! DONT USE A BLACK LIGHT!
Anyway, there are numerous types of lighting you can use for your DT. Myself I would do this:
250w Icecap MH electronic ballast 129.00
lumenarc stealth III 250w HQI double ended MH pendant 139.00
250 w Phoenix double ended 14000k bulb. 65.00
Now this is a tad over your budget, but would be a very nice, very powerful light for your 30 gallon as well it can grow with you as you tanks grow in the future. As opposed to a fixture which may not. When you get a larger tank, you can simply add more of them. I recommend the ice cap ballast because it can fire any 250 w MH lamp. So it's flexible. The lumenarc reflectors are awesome at delivering the light to the corals. You will absolutley be able to keep any light needy specimen in the tip top condition. You can raise and lower the pendant when acclimating corals.
Of course there are many in your range that you can get that will be fine also.
