I would go with the 600, it's only going cost like 50 more bucks, that means you only need to produce 1/4oz more weed with it to make a profit. 1000 is probably over kill for that space, unless you want to build a bigger space, remember, you will need somewhere to put your fans, maybe a de/humidifier, even a heater.
It's my first time to, and I'm getting on real good with DWC. There is a lot to it, you will have to read and read and read, Befor you start. but if you have the time I highly recomend it as a way of growing.
The thing I have found i with hydroponics is that there is more to it, but as long as you are aware of the factors, it's a lot simpler.
As for airo ponics, ment to be even faster, I haven't tryed it yet, if you decided to go this rout, I would recomend getting a back up power supply, for the pumps. If the Ellectric goes off in DWC you have 4 hours befor things go bad, in ario you have like 30 mins. Thats the scaryest thing about it and the only thing that makes me feel uneasy.
Ebb and Flow is ment to be very newbi freindly. but maybe a little more comlicated to home build.
Top Tip DWC: If you are getting rubbermades for DWC get 1 spare, use this for rez changes, make up your mix in the spare rubbermade, make it compleatly correct, Temp, Level, PH, PPM, and then simply swap the lids around, so your plants are now in the new rez and push it back under the light. For this to work properly you must have no lip or step into your room.