Hey Dabberking, I used to have a 2mx2m which is about 6.5feet x 6.5 I believe. I ran 3 600s in cooltubes. 1m was for movement space, I then switched to a 2.4m x 1.2m so I could put all 3 cooltubes in a straight line and avoid bends and increase airflow to lower temps. I never used AC but I live in a colder country I imagine! What I have always done is run 3 lots of flowering stages, each has 3-4 weeks veg, so I harvest every 3-4 weeks. I have never been exact so sometimes it might take a week longer. I veg 4,5 or 6 plants for then put them into flower. I never maximised my yield or space because I don't like to have massive plant numbers. If I were in the USA I would not have that worry!!
Anyway, 2 things to think about.
1, cool tubes are not the best footprint, they tend to not cover a 4x4 that great, however 4 with overlap will probably work better in your space than mine in a straight line.
2, you wont be able to fill a scrog net in two weeks of veg with 2 plants. You may want to think about more plants without a scrog or shit loads in a sog. if you scrog plants in a veg area how will you transport them to a flower area while in a net?
That is if I have understood your intentions for harvesting every 2 weeks.
Also don't count on a strain finishing in 8 weeks from 12/12
Anyway, good luck with what you decide.
Edit I grow from clone obviously