With the CFL's I would go with 4 42 cool white, 6500k. You can use them threw veg and depending on your temps you might be able to keep them on during flower with HPS. Believe it or not that little 150 will put out some heat, so before you get 2 or 3 computer fans you might just want to pick up a 280CFM Squirrel cage fan for $90 or so. Also, you are going to need that light very close to those plants or they are going to strech, the 150W doesn't penatrate very fardown into the plant, try to keep it under 12 in if at all possible with the heat. Think about a home made cool tube, look it up in the FAQ. I can't remember if you can use one on a 150. This will give you the best performance from it though.
Adieu