Nova extreme fixtures are cheap and good for some things, like LPS, Softie, and Fish-Only tanks, but their reflectors are not as efficient as other T5 fixtures. Of course, you can just get one with a million bulbs in it and keep anything, but per watt metal halides are still the most efficient form of lighting.
I would recommend a 250w HQIs and big lumenarc or lumenmax reflectors. 1) even if you are only keeping LPS and Softies, they will look better under MH, 2) IMO the 250 MH is the most versatile light in the hobby. You will always have a use for it, even after you move on from your current project. But if you go with the Nova Extreme, I agree that you should get your own bulbs.