I'm just quoting from my grower bible but it shows a 150w covering a 2x2 (60cmx60cm) at 12in above with a "good" hood so you might want some cfls 2700k for flowering and 6500k for veggin to help boost that if you have a bigger area.
You really do need a larger light. If that's all you have to work with, then keep them small and surround them with reflective material to make the best use of the light you do have.
You could also just grow the seeds 1 or 2 at a time.