If your building a huge box dont forget Ventilation! an inline fan works great, but if you can drill a small 4'x4 'hole in ur wall ur set! Squirrel cage fans are noisy, but if you place some rubber padding underneath it, it wont make nearly any noise. ANd also check out getting some Mylar, i got 50 ft. for 14 bucks off HTG supply.com and it makes a hell of a difference. This place also has some cheap inline fans under ventilation, you should check it out and it will help provide you with some ideas. You should spend just as much money on ventilation as u did you light.....ok maybe a little less. but check it out. Goodluck