if your doing sog i would two 4x6 and fill it completely up depending on how many plants and how filled it is will depend on how much you should cut off the bottom becuase ive trie both and i think its a waste to cut some plant off unless youre stuffing it to an almost unlikely level. but if you do some research im not sure what its called but i know someone who bought something to hold 200 plants uner a 1000 watt and he pulls a pound each time. are you going to plant one table then wait a month to plant the other one?