CFL's come in all spectrum that's why. you can get a cfl with a temp of 5500k or 3000k.

obviously 5500k is going to be better for vegging.. then you impliment the red spectrum for flowering. the MH may have more light intensity.. but it's not really ideal. you can get these cfl's online... in all kinds of spectrums.

most of the time, no.. you don't need a special ballast.. just a simple light socket