Current USA`s Nova Extreme lights...

I'd get a different fixture if I was you.  The nova extreme is not very good for a few reasons and will have you wanting to upgrade as soon as you have them.

 

I have the t5 extreme, and i feel like it's good for the price. but i'd replace the bulbs after 6 months. The pro would be nice because of the individual reflectors but when they say it's a woopin 300% better, i think their comparing it to having no reflector at all, not to a fixture with 1 contour reflector like the extreme.
you would want to keep in mind though that those current bulbs do suck, and new bulbs for that fixture would cost you around $200.

 

Sorry for being so non specific. Here are some Pros and Cons with the nova-etreme.  My only experience is with their four lamp model.

Pros: 
The Price:  It's matched to the quality
2 Lamp switches:  this is nice for a dusk to dawn effect
Moon Lights
Cons: 
The lamps:  They throw off very little compared to most T5 lamps
The Legs:  I've always worried about breaking them they are not very sturdy
One uni-reflector:  The individual reflectors are so much better
The fan:  One just is not enough and almost pointless for cooling the fixture
I found that the nova extreme was ok for my 55.  I had it on my 90 for a short bit last summer and it was not nearly enough light.  I threw some URI and ATI lamps in the fixture and it dramaticly helped the light output.  It still seemed very poorly lit though in my 90.  I ended up getting a icecap retrofit for my 90 with the SLR's.  I'd guess that the retrofit is easily 300% brighter.  After each time I improved the lighting my corals increased in growth and color.  I just added a two lamp TEK retro also to my lighting system.  The TEK retro came with a normal workhorse ballast so they are not as bright as when driven by icecap's.  The new reflectors are very comparable though. 
In conclusion, I'd have to say in all that the Nova Extreme fixture was very expensive for me.  Why?  Because I replaced everything on it to get what I wanted out of my lighting.

 

 

Go with the Nova extreme Pro. Even though there is only 6 bulbs, it does have contured reflectors. They are not individualy contured, it is one sheet bent around each bulb. The Pro will put out more light than the extreme because of the reflector. I have a pro, and am very happy with it. My only negative is that if you are adding anything to the tank and want to float it, you have to move the light to do so. Also there are no moon lights, but those arent really needed anyway, unless you are trying to breed (from what I understand anyway).

 

RobynT is selling a 6 lamp T5 fixture if it is not sold already. I hear they are pretty good.

 

My experience has been that my TEK light fixture has always worked flawlessly and is a quality made product.  There are two separate switches for control. I don't think I would want any more light over my 90 than this fixture puts out. 
I know a guy that had the Nova fixture and ended up selling it and replacing it with the TEK.  His opinion was that the Nova didn't do a very good job. (Sorry!)