jaxx, i just got back from camping, sorry about the long wait for an answer! i used 1 inch screen and tried to space them so there is only 1-2 budsites per square, which isn't always possible but as long as the budsites aren't one right on top of another you should be fine. i had 2 smaller flower chambers that measured just under 2ftx2ft and were under 3 feet tall. one had 350 watts of assorted cfls and the other a rewired 150hps security light and 164watts of cfls. i would recommend the 150hps. suprisingly the hps chamber ran 5-10degrrees cooler than the cfl only chamber with the exact same ventillation (180cfm exhaust and 2 4inch inline fans for intakes, one above and one below the screen). not only did it run cooler, i got at least an oz more bud at harvest and it was much better quality as well. you can get a 150hps security light at lowes for under 50bucks if i remember correctly. all you have to do is remove the photocell and rewire it so it is a remote ballast system, it's really simple. as for yeild the most i have heard anyone getting is 2.4oz per square foot. my 2 small chambers were aprox. 3 and 3/4 sq.ft and my best yeild was around 6oz but you have to also realize that i only had 314watts and 164 of those were cfl so getting 2.4oz per sq.ft was not possible under those conditions. honestly, i haven't come that close to 2.4oz/sq.ft although i have almost achieved 1 gram per watt. good luck with your new set-up!