Ok, PC GROW BOX dude, I am in the same boat as you except I have 17" case, and bag seed from bubba.
OK, to add more light take a brown extension cord and two sockets and black tape them on the end of the cord and add bulbs.
Move to the front of case.
For fan get PC fan and DC Power supply and black tape connections first and test which way is intake and outtake.
For reflectivity Wal Mart reflective windshield cover and glue gun works wonders.
Hopefully you have earth magnets on your light with power strip and sockets as that will make it move easily and safely (no reflective on back)
Hope I helped. Ask away as I built my box for $60 and its 150 cfl watts and is crusing along.
I reccommend Auto Mary for this size box, and a 2.5 Liter size food saver dish for soil.