Don't count yourself out on HID. During Veg I would use the CFL's. But my research shows that 150W HPS will produce less heat than your 180W of CFL's.
Just think... If HPS produces more lumens per watt then the assumption can be made that it burns cooler. Since more electricity is transformed into light, then less electricity is left to produce heat.
I could be wrong on this. But none have corrected me on it.