Hey I was considering doing the same kind of set up in the near future... you should check these out. I found them on BG hydro and they are dual 600 watt, either conv. MH or HPS bulbs, hoods of your choice and they are run off a single 1200 watt ballast that splits power evenly to each hood. I myself was looking to run 3-4 of these ballasts... giving me either 3600 or 4800 watts with some insanely great light coverage. I was planning on running these over a 5-gallon DWC/ Ebb and Flow recirculating system which I think is going to be killer...

http://www.bghydro.com/BGH/items.asp...atus=0&Tp=&Bc=