You have to consider far more than just the size and number of plants. Even adding a lot more light doesn't necessarily equate to larger yield. You will have to worry about proper ventilation/cooling with a light of that size. How much space are you working with? I think, in any case, that expecting 7 oz from EACH plant, on a first grow, is chimerical to say the least. In fact, I would dare say, impossible. Provided you get the 600w set up and ventilate it properly, take care of the plants IDEALLY, you may get 3-4 oz per plant. That's still a big haul given the number of plants you're working with. Keep your expectation very modest, especially for a first grow, and you won't be disappointed. And as far as finances, don't even expect to recuperate your expenses on a first run through. There will be many adjustments necessary before you get everything dialed in, and it may take a few grows until your investment becomes worth it from a pecuniary standpoint, whether you're just saving money by growing your own or selling your product. GOOD LUCK! and don't take this as harsh or intended to crush your dreams. Just scale back your expectation BIG TIME, and you won't be as bitterly disappointed. Right now your setting yourself up for a big let down when you get a couple ozs off each plant.