Which pots to use? Considering the limited space ...

Don’t think you can fit 3x3 gallon pots in that space but maybe 3x2 gallons? 1 gallon will fit but they’re a little small so 2 gallon will give your roots a bit more room finishing out this grow. 2 plants in 3 gallon pots would look to be ideal for your space. All the best growing forward! 😉

Those Have been good to transplant for a while now :) you should transplant them into a 3 gallon pot this will allow you to continue to veg for a while then finish your flowering stage with no problems , your plants will also remain under 4 feet tall each which should help you maintain a good space for your plants to grow being that your limited on the space you have . I wouldnt go 2 gallon cause your plant wont be able to veg for much longer and that will lead to less yield in the end of things , 3 gallons is perfect for your space and what your trying to do :) . I hope this information is useful to you on your quest to becoming a grow master ! Happy Growing!