You should be ok with the 600w HPS, just be REALLY CAREFUL of the heat. The 600w HPS is gonna be around 90k lums, a 1000w HPS should be around 140k Lum's and more heat! Before dropping in around 20 plants in that area, i would get just a couple to grow in there so you dont loose your entire crop, just a suggestion tho. A trial run is always good for a new setup and keeping it small you can address any problems that may come up before it effects all of your plants.

Good luck on whatever you decide to do. :jointsmile: