Regular ol' screw in bulbs aren't going to give ya shit! For something that size you could go with CFLs or Flo's. Check out the chart below for the light spectrum.

I saw on here once where a dude made like an octogon with flo's standing up. If ya go that route, use soft white with cool whites. DON'T use the daylighters or you'll torch your plants. Good Luck!! :thumbsup: