Flourescents wont work,especially cool white. Since your on a tight budget you probably want to get some CFL's.They're cheap and you can position them pretty well to for light penetration and such. Your buds are deff gonna be fluffy, but with CFL's instead they might be a little tighter.

Also if they're getting to big have you tryed trimming them back some and topping them? It will give other branches more light,as well as you can keep it's height maintained. Plus it will let other branches break through to the top to try and become top colas from all the extra light