Hey man, Well if you are looking for cheap grow lights CFL's would be the way you want to go.

But if you wanted to do it the way with the two proper lighting systems [ The way I like it lol ] You would want to go with a HPS/MH swithable ballast. Strictly because the MH[Metal Halide] light gives off the blue spectrum light wich the plant likes during the vegatation stage of her growth, the HPS[High Pressure Sodium] gives off a red spectrum wich the cannabis plant loves aswell under flowering. You can purchase HPS bulbs with red spectrum but they also give off a bit of blue spectrum to increase growth. A 400w MH/HPS switchable will run you 150-200$. I would suggest a 600w for your specified settings.

Thats just my 2 cents, good luck