Naio,
I'd research a little more on the output from a SAD light mfg such as Alaska Northern Lights that makes them for use in all of the darkness in Alaska during the winter.
I have the large model Northernstar 10,000 with two lamps of 60W each. I think the 500W light you listed is way overkill.
If I remember right from my reading on SAD lights several years ago, it's to be within several feet of you and while the light doesn't have to be directly in front of you, it does need to be situated so the lights rays will enter your eyes. The effect of the light decreases with distance. I'm not sure how you're going to let a 500W light shine into your eyes from 2 - 4 feet away. I also have my doubts as to the light bar supplying the correct light spectrum.
Also while the light bar will be returnable, you have to do it within 30 days. Using a SAD light does change everything with one or two quick uses so it may take a while to see if the light bar is doing anything for you. Again, I think the 500W is way overkill for this purpose.
Bill
