The water farms will yield more than ebb and flow, and with less waste. That being said, the answer depends on your strategy. If you want a SOG, then tray is the way to go and cram them in there. Alternatively, if you are uncomfortable with that many plants, then use the water farms and grow up to 4 plants. They will be massive and potentially will yield the same as your SOG.

Try your 1000 W. If you can keep the water temp below 80 than you're golden. If not than switch to your 600. That is not really a compromise considering that MJ only needs 10K LUX in flower and at 3X you get that from a 600. (Make sure it's a 95K Lumens 600).