Make sure you recognize that there are two Nova Extreme fixtures--(i) the Nova Extreme HO T5; and (ii) the Nova Extreme Pro HO T5. The Pro has individual reflectors and 2 additional bulbs, whereas the regular Nova Extreme has one parabolic reflector for all 4 bulbs. Individual reflectors make a huge difference (can increase light output by up to 300%), so the reflectors are a BIG difference between these two fixtures above and beyond the fact that the Pro has 2 additional bulbs.
The regular Nova Extreme should be fine for mushrooms, zoas, and some lower-light LPS, but IMO it will not be sufficient for an anemone. If you intend to keep an anemone or SPS down the road, I highly recommend spending the extra money on a fixture with individual reflectors like the Nova Extreme Pro. This will give you a lot more flexibility down the road.
How long is your tank? 30" or 36"?