Well if you get a good strain and done hydroponicly then yes you can get 1lb a plant with 2 1/2 months, thats fair 2 say! Anyting more, good luck and this means you must know your nuts and have a good regulation on temp/co2 levels. Im thinking of this all with in a 4X4 room with a 600W. I dont know if your even going to waste your time with Co2 then (becuase of money) and the 600W in your 4X4room will not reflect very well due to the foilage bocking light from refelcting off the walls to underneath the canopy.. But go with the 600WHPS
)) you will be very happy!
I bet if you go in soil and you use a simple 3part feed, your going to get .5-.75gram per watt, UNless you have a great strain.. .75 will be my guess with good strain. GL though!