I've used the 42 watt compact floros that Garden Knowm mentioned before and they are awesome. People talk shit on floros all the time, but you can be very successful with the 42 watters. I used 8 of them with a home-made aluminum reflector and just kept the lights about 3 to 4 inches away from the top of the plants and the growth was excellent. There was no absurd amount of stretching as many people witness with floros; my plants were bushy as hell. of course i had to raise the lights just about every day since the floros have to be close but not too close to the plants. But anywho, i got a little over 8 ounces off 4 little bushy plants using the 42 watters. I could have gotten quite a bit more too if i had done a scrog. I also didn't need any ventilation. anybody not wanting to deal with heat issues should just go to home depot and pick up a few of these 42 watt CFL, they'll work wonders and inspire you to grow for life.