Toping will work but better on certain strains. Also if your using CFL's you dont want them too bushy because you'll need more light to cover the larger pants, taller may be better for you. Ive grown using 2-65watt CFL's from lights of america and 2 extra 40watt daylight bulbs, all were 6500K. I had 5 large plants under them and yeilded about 3 dried ounces, I also added a couple xtra soft white cfl's when put into flowering. You have to have the bulb right next to the plants, within inches and you should have success. They also dont put out very much heat at all so dont worry about the plants getting burned, CFL's are great for small grows.