yea, i use a mix of the 26W's and the 42W's and i used a total of 9 CFL's for 4 plants.
though when u go to flower id suggest u either get a diff lighting system or get a few 42W CFL's.
To flower I'd use 12 48w cfl's.. On top, and around the sides. Much better light to all parts of plant, plus, if a bulb burns out, no panic, just go to HD and replces, with hps/mh, unless you've a hydro store nearby, then ..bye bye baby bye bye...