i'd do 2 600's with 4 plants under each one along the back of the closet. 600's have a 4x4 footprint roughtly. that way you'll have 2' in the front of the closet for any other equipment you need. if you can get a 240v outlet into the room lumatek makes a dual 600w ballasts. costs about $250 and controls 2 bulbs from 1 ballast.