Since you're thinking about expanding plant numbers for SOG, I thought I would share my experience. In a 4x4' area I have tried 25, 30, 36 and 49 plants. So that's a 5x5, 6x5, 6x6 and 7x7 formation in a 4x4' area. The denser you go the more the plants will stretch. You also need to factor in the indica/sativa ratio of your strain for optimal results. So your mileage WILL vary depending on these factors but the optimal I found was a 6x5 setup for 30 Jack Herer plants, a 70-80% sativa dominant. With a 5 day veg from 1.5" clone, a 5x6 setup, a nice even canopy resulted 28-36" tall, which is what you should shoot for with SOG. So you will need to play with your veg period to hit those heights depending on your strain. Don't forget to cut bottom 1/3 of plant, W2 and W4 of flowering of course.
I think the ideal SOG setup for a 4x4' would be something like this:
X-X-X-X-X-X
-X-X-X-X-X-
X-X-X-X-X-X
-X-X-X-X-X-
X-X-X-X-X-X
...where X is a plant. Cover that with a 1000W HPS (or equivalent), dial it in, and you should hit 2lb.