Your ballast doesn't put out 1100 watts I don't give a shit what the setting, the manual, or the joker at the hydro store says. Just chill and listen a second.. Your plants can only take up so much light before you are wasting it.. In a 6x6 area you don't need 3 600s. I don't believe you will pull anymore nug than if you only used 2. With that being said, you aren't going to listen to me. But it's ok, learn for yourself.
Saying that you know how to Top, fim, and lst , a plant , which you could easily do to any plant, doesn't mean that you are some grand master grower. You could easily do this to a rose bush.
Saying that your trying to get 8 ounces from a plant that you don't plan on topping or lst leads me to believe you don't know what you are talking about. Are you going to be using co2 in this room?