8 plants in 30 gal jugs. what lights should i use?

I may scrap the SoG style grow i am going to do. My dad (yea my dad grows with me ;] ) my dad thinks its better to grow 8 plants in large pots under 2 1000 watt hps lights with co2. should i use 2 lights or 3 how i was going to do with the sog.