For those who don't have a Lowes: http://www.1000bulbs.com/category.php?category=2086
I was going to do this same thing but decided I didn't like the idea of squeezing the bulbs into such a tight space. I have the full All-Glass hood and the bulbs would actually be sandwiched in contact with my glass lid and the hood reflector.
Mine is the same way, actually did a test run on them earlier by letting them run in there for 3 hours and neither the top of the hood nor the glass underneath felt nearly as hot as they did when I just ran the regular incadesant lights for them, you should seriously give it a shot, makes the tank look oh so bright!