Quote Originally Posted by bud luv
A few thoughts:

-You can fit a lot of plants in a 5 x 8 space. A lot of plants need a lot of light. You could EASILY do with a 1000w HPS in there, two of em if you can exhaust the heat. A 400 watter (or CFLs, especially) is going to limit the upside of your grow.
Do you know if using these are common? And if so how noisy they are?
http://www.elights.com/1000hpsgrow.html