i have a single plant too, stealth grow... i'm only using 2 CFL's, and i've noticed it's MORE than enough for just a single plant. mine's about a foot tall so far, into flowering, everything is extremely healthy, it's growing fast, and all I feed it is molasses. I'm already noticing trichomes on the leaves, blah blah blah.
pretty much you're more than set for a single plant, yours will look even better than mine. don't worry about people using 200-400W HPS or 6-8 CFL's.... those are for bigger grows or people that don't wanna take any risks.