Sounds good to me. First question you want to ask yourself is how much supply do you need/want to get from this? You've already said the space you have to work with and the lights, the other main thing is the strain you're growing. I'd say you can flower 1-4 plants to a decent size, 4-10 small plants, or up to around 80 or so in a SOG in 20oz soda bottles. If your skills at growing are good (first time so it might take a few grows to get it), you can harvest possibly up to 1/2 lb from your setup each grow. With SOG you can rotate up to 10 plants a week through there and harvest about 1/2oz for each but this takes a fair amount of skill and work, as well as putting your plant count at dangerous levels if you should get caught. With that size space, your light is on the low end and an investment in an aircooled/cooltube 600w HPS will more often than not pay off with higher returns but you're still good now.

Good luck and don't get discouraged, most people don't get it perfect their first time around but the more research you do the better your try will be.