I agree metal halide bulbs are for huge enclosures. See if you can find one of the new ZooMed ReptiSun 10.0 bulbs they are awsome. They penetrate UV 20" from the bulbs serface and are currently $19.99USD (about $23CND any size) from
Big Apple Herp Supply .
I currently use Exo-Terra (Hagen) 8.0 and will be switching over to the ZooMed ReptiSun 10.0 for all 15 of my dragons as soon as I can, as I feel the 10.0 are a better bulb and offer more to my animals than the 8.0 do.