Hi baldy,
My flower room is 1400 watts total- different lights though, just a 1000 and 400, but the room I run them in is 5x6 feet. With the smaller lights, you have a little more flexibility for how you want to arrange your space- you can do a longer narrower room- I'd put the big one in the middle if you did that.
In addition to your intake, you are going to want an active exhaust.