Complete ballast HPS system

I found a complete ballast system for HPS that I am keenly interested in, but the highest wattage I found was 250. First question... is 250 watt HPS enough for a 3-4 (indica in the closet) grow? Here is the link with a complete description:

http://www.1000bulbs.com/product.php?product=6282

I'm interested in this because its a complete system, all I would need to buy for it is the bulb itself (I'm assuming they mean bulb in the advert, when they say lamp not included). But... the big attraction is the plug and play. I wouldn't have to rewire anything in order to use it. Right? God I hope so, because I have no clue on how to wire anything in or rework current wiring. An electricion I am not.

So, does anyone have anything like this, if so I'm all ears. Or if anyone is familiar with these and their ease of use I'm all ears. I don't really want to plunk down the money for one of these to find out I have to wire it into my walls or anything. I just want to screw in the 250 watt HPS bulb, plug it in, and have light.

Thanks in advance :)