Yes I use the 150W Security lights(paid $48). I just took it apart and re-ran the socket wire, Now my ballast sits on the top shelf of my closet while the bulb is attached to a DIY reflector.
To roughrider, I think you may have overlooked the MH light he already has. That plus a 150W HPS should do the trick.
I'm a light hog as well, I've found that although your space may be 2'*3', You may only use 1.5'*2'. I've solved that wasted light issue.
I've used big posterboard setup like a tabletop pictureframe. This way I can move the walls closer or farther. The posterboard is white so it reflects without heating up(meaning my leaves can be touching this type of reflector).
I use 2 150's in my 3'*6' closet, But my girls never take up more than 2'*4'. I LST to create 2'*2' girls.