2x1000W OR 3x600W? Direct me with your supreme knowledge!!! first hydro!!

I am running an SOG flood and drain system using hydrocorn in pots. The trays are 2x4 feet and there will be a total of around 64 pots. There will be NO veg, only flowering. We will NOT be using a tent and we will spend as much as we have to on ventilation. Any light we get will have a cool reflector or cool tube. I do not know whether it is more efficient to use 1200W or 2000W. We can either set the trays up longways. against each other or top to bottom. Thanks guys for all your help! Im usually an outdoor guerilla organic fiend, but theres a first time for everything.

That's a hard one what size pots? I like the idea of the 600watters. Your can get them lower

I think like 8inch square pots maybe a little smaller. Its about 4 plants per sq ft.