Sounds fine, as long as youre not growing really tall plants. Keep em under 3 feet or so and the 600w's should be ok.
Do you already have that 400 though? I think 3 600s would be better.
I dont think you'll need the fluoros if you have good reflective material on the walls.
ya that would be good for like 30 plants
Can someone tell me how much distance should be between my MH and my 12 day old plants. Have them on 75% power now under 400 watt. They look good but the two autos I have are so small. One looks like a mutant. Only 2 leaves and they look screwed up. Auto Bomb. Have 5 plants in a 4 x 2 foot space.