If you can get the heat out 6oo would be cool, however ive said on this site before i have friends who run 1000 watt hid lights and i get much better results with using 400 watt, mylar is a good thing to bounce back the light, i also have a friend who just uses a 250 watt and always gets good weed from 3 plants in a small 5ft by 2 ft cuboard, big powerfull lights does not always give you more weed, put in the time and the love you might just be surprised what you get, happy times friend enjoy the months ahead.