If I'm not mistaken, most of us use UVB, not UVA. I think the most popular is the mercury vapor bulb, but quite a few folks use the tube-type fluorescent. In my opinion, they don't work as well. No UV is required at night. If your house is too cold you can use a ceramic heat emitter (heat without light) or a black/red light.
UVA is helpful in some ways, but UVB is necessary for good bone health and development. Since all UVB bulbs also put out some UVA (usually 2-4 times more UVA than UVB), you don't really need a separate bulb.