Maybe I can give you some helpfull advice as I have seen what a person can do with DWC. What I like to do is have a bit bigger plants in DWC buckets and set it up like a perpetual harbvest.

You can go 4 rows of 4 or 5 rows of 5 with small plants , so thats like 16-20 plants in a square. But thats alot of air pumps!!

You shold go with 3x3 under a 600 watt hps so thats 9 plants. You might be able to yield 1-2 oz per plant.