I don't think it will be enough at all. (4x40=160)+(2x20=40)=200 and I currently have 300 watts running to my 3 plants and I don't think mine will be enough. Thankfully I have someone on these forums helping me out there ;-). But from that person I've learned that the best way to grow in a closet or small space is to probably have a few CFL's or other floros real close to the plants and an HPS/MH above to provide that extra heat. This in turn makes the plants NOT reach for the light but still have that awesome light power from the HPS and not get burned. So it's a win win situation. Bottom line, the more light and less heat comming from the light the better. Also from what I've learned, floros produce small buds regardless of how big the plant grows and you need HPS/MH to get a big yield.