Also, let me explaine this to you since no one has commented on it. With SOG you are putting 2 to 4 plants per SQF so under a 5x4 area you could put 40 to 80 plants. With a week veg you may only turn out about 10 grams per plant, maybe a little more. IMO if you only want to grow out 40 and use 2K in lights I would veg them for approx 3 weeks once rooted for best yield or you may only get about 400 grams which is fine, but you should be able to do that with 1000W, and in that case you are kind of waisting a whole 1000W.
Adieu