Help? 15x8 shed 8x8 for flowering

Ok. I'm new to this so please roll with me. I have a shed in my backyard that is roughly 15x8x8 at the peak of the ceiling. My plan is to section it off at 8' making a square room for flowering that is going to hold 4 Radiant 6 AC hoods with 2 600w Lumatek Dual ballasts. My main questions are going to involve AC, and CO2. What type of AC can/should I get? Do I even need CO2. My best friend has a slightly larger setup and he does ok without it. I am still a little cloudy on running the ac/co2/carbon filter together. Any advice would be very helpful. Thanks.