I use a 600 hortilux in a 3.5 x 2.5 area and have grown as many as 14 plants. I only grow 6 at a time now ... but I use an aero system instead of Deep Water Culture (DWC). The yield is anywhere between 8 - 13 ounces of quality, finished bud, depending upon the strain. Two plants under a 600, if grown in a Screen of Green (SCROG) style should yield more than enough for your personal use and some left over for your buddies.
Grow your seedlings and root your cuttings under a couple of two-foot, twenty watt floros. Then transfer them to the 600 and keep the light three feet above the plants at first. Then, over a several day period, gradually lower the light ... then keep it around 18" above the plants for the rest of the grow.
Vi