I built my own. Like others have said, you're more free to customize it to suit your needs and setup. Prebuilt ones are really expensive. I used a spare tank and skimmer I had laying around, I work at a hardware store so I got free glass and plumbing parts. I only had to buy a return to complete...
looking good, you need to add some color though. One of the best pieces of advice I got from my LFS was that your tank is like a piece of real estate. There is only so much room in it and to fill it up with bland (brownish) colors is wasteful. Save your money and buy some bright colors rather...
That would be great. I only have MH's; however, it's a 250w for a 37 gallon tank. Now that you say that I think it's true. I have a coralife mini over my sump, which has been hooked up for about 1/3 the time of my DT and it has coraline in it.