Single 600watt, double 600watt, or 1000watt?

I'm thinking of upgrading to a 12 or 16 plant recirculating deep water culture (RDWC) setup and am wondering what light(s) to upgrade to. I currently have a 430 Watt HPS that will be used with some fluros for the mother clone room. But I have a good sized room for flowering and want to give each bucket plenty of space so plants can branch out and light can penetrate easily. The dimensions for this flowering area are approximately 8w X 10l X 8h. but I can go even wider and longer, just not higher.

My question is will a 600 watt suffice, or should I consider two 600 watt lights, or a single 1000 watt. George Cervantes clearly advocates in the medical bible that 2 x 600 watt is much more efficient than a single 1000 watt and you can let the plants grow closer to the lights. But I'll go with a single 600watt if it's enough.

Thoughts?

id do 2 600w in that space. Some will say do two 1000w....but do not use 1 600w, or 1 1000w

2x 600w all the way

600w hps is the money number
my dream garden would use 600w hps lights on movers.

Go with at least 2 x 600 watt and they will perform much better.

Your better off with the two 600w. Or you could go with two 1000w, with that space.
I have 4 1000w in a similar sized space and it works great for me.

you'll get more points of direct light with the two 600's then you would with one 1000.