the more lights the better, but depending on how many cfl's you have you can get away with just using those up until flowering if you wanna save yourself some money on electricity
as SoY says the more lights the better, so yeh go for it mate also as said can save dosh on cfls but go with hps mate much much better, more yield better potency, but still get good quality using cfls, your choice . whatever way you go ,all the best