1000wtts is overkill in that size room. ofcourse if u got ur shit set up correctly u dont have anything to worry about. Ive got the same set up, 1 400wtt hps in 4x2x7 area. Which gives me killer ladies. so a 400 is def enough maybe a 600 but u need to consider temps, mine are a bitch some days i need to keep my outside room 69F to keep my g.r. at 85 with lights on. I have a carbon filter on a 465 daytona blower and my temps are still reachn 90 some days, i really need a vented hood.

Hey if you have the room to grow tall girls i wouldnt bother with scrog, it works very very well with hydro but its more for limited head room. and u wont get as much if u just grew them normal, i would say do 6 plants and just let em grow