im actually a noob so please be sure to double check me on this.
but with that said.

I believe a 600W HPS on 3 plants(possibly 2) should be 8"-12" from the top of the plants. Im not sure if you have one but i hear light movers, when done right and safely, are very helpful and beneficial. Something to look into.

Also i see in the op that you have 1 200W "red" envirolite and 1 200W "blue" envirolite, once again excuse me i too am a newb, are these cfl? or a light that may be you could also run vertically to help with getting the lower, harder to reach, buds/branches. Disregard this if it is of no use to you, but just a thought.

More light means better buds right?

I demand an update though!!