Like IDS says depends in your growing space and also your airflow. Think removal of hot air to outside the grow space and intake of fresh air from outside for cooling and also vital fresh CO2. Dont' forget a carbon filter to scrub the smell of the plants out of the exhausted air.
Like chsmo says you can do some ok / decent grows using CFL but he used 414 watts of CFL lighting there. Personally I'd probably just grow with a 400 Watt HPS though. CFL are great for veg, don't make as much heat, but HPS can beat CFL for flowering. Still though nice grow chsmo with the cfls.