Hi, I built a box that is 40" wide, 48" tall, and 20" deep and am not sure which light to get. I am looking at the Sunburst 250 MH/HPS and the Sunburst 400 MH/HPS, both with cooling options. I want enough light to handle about 6 plants in this grow box and hopefully not create too much heat. I will have some kind of air ventilation setup but not sure exacts on that yet. Which light do you think is best for this size box and to grow about 6 plants? Thanks!