Well since they don't make a 600w MH you'll be using a conversion bulb for the 600 any way you look at it.

I'd say go for gold, get the 1000w digi (Lumatek are good) and simply use witch ever bulb you want.

Of course if you're hurting for money than you should simply spend the money on a conversion bulb for the 1000w hps you already have.

Hope this helps.
Bob.
BobBong Reviewed by BobBong on . Need Help!!! MH Decision Making Hi Guys - I have a decision to make, and i was hoping you guys could help me choose... i am on a tight budget this month, however, i need mh lighting for my vegging... I currently own a 4 bulb 4 foot new wave fixture (216 watt, 20000 lumens, 6500kelvins) and a 1000 watt sun system ballast system (using hortilux super hps bulb)... I plan on planting 30 plant seeds, hoping to get half females, which shouldnt be to hard of doing. What i need help on deciding is, what should i do, get a Rating: 5