I have had 2 grows with cfl's and thinking about moving to hps or mh. Is ther a 1 bulb system that I can use? I would like to stay the 400-500 watt range in a 3' wide by 4' tall by 2' deep grow area. Should I use 1 hps bulb for both veg and flower or should I get a lower watt mh and a lower...