Quote Originally Posted by Rusty Trichome
Do you have the lights already? If not, get one, and try the sucker out. This will give you a good idea on what you can and can't do from there. Otherwise it's just speculation.

7 x 7 is a very small room for two 600w lights, and they would likely need the heat exhausted aggressively. (unless you live in Alaska or Siberia)
What would be the proper way to hook them up?

Open Hood 600W > Ducting > 600W Hood > Inline Fan > Ducting > Inline Fan > Scrubber ?