wow, just looked it up and yeah no kits listed like the old ones.
I got a 5x5 and ended up going with a Photontek 1000W Co2 pro. It was right before they came out with the regular 1000W. Generally happy with it but pricey! Also, not much blue in the spectrum so I supplement. I already had the light controller since I have a 600W so that weighed my decision a lot. Have to take two of the middle bars out as it's too powerful!
Think for the price, the fc8000 is a great deal comparatively. Fruitz has one I think.
Most lights designed for 5x5 are $$$! I was looking at Grandmaster Leds Tarantula Tent Ultimate recently. Have seen some good stuff on that company, but once again pricey. Think it is $1200. They also make a 730 watt for a better deal. Wanna say it was a little over $700 and seems like a great deal for the price. Would look into it a bit more before pulling the trigger...
For the price, would personally go with that Grandmaster for 700ish or the mars