HID lighting, even with the ballast, tends to be a smaller initial investment than the bunch of CFL's and all the sockets, cords, etc you are going to need to get to set it up properly. Plus, the light emitted by HID lighting does not degrade as severely over distance (better penetration to lower leaves) as CFL's. However, if you are set on going with CFL's (since to the best of my knowledge no ballast free HID lighting exists), then just keep in mind you want at least 2500 lumens per square foot (more realistically if you want a decent harvest), ideally 5000-10,000 lumens/sqfoot. Keep that in mind when you are deciding what you want to do.