I would go with buckets on this one. 5 gallon buckets, this way you have control over what each plant is doing. If you happen to have a male or diseased plant you can just delete that plant from its own bucket without disturbing the grown-together root mass of all the other plants. In order to grow large plants with ebb and flow in a basin or tray you would need a pretty large basin or tray. On the other hand, you could scrog those 12 plants in a tray and that may produce a nice yield. I still think you would need a huge try to make it worth it.