I would invest in a 250W HID light instead of having 16 cfl sulbs hanging all over the place, but if that's all you can get then the more the merrier. You won't draw that many amps so don't worry about starting a fire. I would get a power bar or two to make plugging in the timer easier.

I doubt you'll get 6 dry ozs without a HID. Look for 3-4 ozs dry if you add the extra light, around 2oz if you don't.

Let us know the results.