Your asking mostly for opinion here.
GG, 9, 7 gallon pots in a 4x4?
I call that overkill...especially 4 SCROGing.... Hell, a 4x4 and SCROG done right? You could do a 10 and use 1 pot and do well.
I liked 3 gallon pots - up to 6 but, you get crowding issues as they get over 34-36 inch's.
4 pots, 3 gallon, water/feed the plant everyday (the right nutrient ratio's) and you can get some real high quality....Grow to between 4-5 ft..