well ive got a 1000 wat sunsystem lamp but is that to big for it but i dont want to use it yet b-cause it runs on 220v. these will go in a 5ft tall by 2ft wide by 2 1/5 long area. quote]
well if you alreayd own the 1k system, you should stick with it. space is never an issue for lighting beyond the placement of the fixture.
the bigger the better with lights- as long as you can handle controlling the heat (and the elec bill.). more watts = more good stuff like lumens for the plants, but it also means more heat which can be potentially harmful. so if you can put it in your area and be able to maintain proper temps, you are benefitting from using the 1k over anything smaller.
if you dont own the 1k yet, you are fine with a 400-600w system. i just dont see a reason for you to downgrade, or spends more $$ on lights that you already have.