Hi Frances,
I also get the winter blues if I don't get enough light (which can be difficult at times living up in the Pacific Northwest). As somebody who has studied lighting design, however, I can tell you that studies have proven full spectrum lamps do not help any more than regular incandescent lamps. So buy whatever kind of fixture and lamps you want--incandescent, fluorescent, or full-spectrum because studies have shown that it doesn't make a difference for SAD. Most people just don't use bright lamps consistently enough to make a difference. I've found that making an effort to turn on the brightest fixture every time I enter a room when the weather is grey (even in the middle of the day) is all it takes.
Cheers,
Dorie