You're asking all of the hard questions! I'm looking at whatever I can fit in my space. My thinking is constantly evolving here. Originally I sent of 3.5 square and figured on 3 - 4 plants at 4' - 5' tall. I've done a few out door grows with mix results and that was years ago. I'm pulling this together with decent resources, a willingness to learn, and passion for mastering whatever it is I turn my attention to. The LEDs are looking better and better.

So I guess I'd veg. to 12" - 18" inches and flower 4 - 5.5 feet assuming I can light it properly and strain dependent (obviously) along with all the other variables. If I go LED I guess I need to consider ScrOG too. I'm guessing that each plant will want more than 1' diameter.