ive only seen the switchable ballast in 400 and 1000 w lights but i havnt shoped around too much. i originally wanted to do 600s too but decided on a 400 switchable first then when i can afford it get a couple of 600s hps(ive seen a ballast that can run 2 600s) and use the 400 for veg. obviously you are thinking much larger. good luck but as some one said all of those lights will be hotter than your ac can handle. and to vent that large of an area you will need some very powerfull fans.(noise) obviously you wont be covering every square foot of floor with lighting either. best i can think of is to do some figuring and section off an area that will handle the space for your lights. then cool that area and keep your ballast and heat generating appliances out of the grow area and vent into that part of the basement. a plus lol you might heat your house with your lights.