I bought my light box about 6-8 years ago from Alaskan Northern Lights (they have an Internet site--mine cost over $400 and was worth EVERY penny.) when I was diagnosed with SAD. Yes, it was expensive, but it was the best money I ever spent. I've been taking Vit D-3 for the past three years now, so my Vit D-3 level is quite high. I have gone off all antidepressants and don't need to use the box as much as I used to.
For anyone living in the northern climates like those of us in the Midwest, a lightbox is almost a Savior when it comes to winter and the winter blues because we're not exposed to as much sun. A good quality lightbox, I believe, is still better than a lot of the full-spectrum lights, although I've heard for some people they work for them. In fact, I have three lamps in my home office that are full-spectrum, and I turn all of them on in the winter time (I don't usually use them in the summer months).
I will say, though, that the therapy lightbox light is BRIGHT. If you work around a lot of people or are out in the open, your light will bother others. If you have your own office and can somehow block some of the light's brightness, that might work. But the kicker is that it needs to be at eye/face level for the light to penetrate your eye/soak into your facial skin, so you can't "hide" it very well from others.
Good luck on your search. I did want to mention that the company I bought my light from has been wonderful to deal with, and they've never gone out of business. I've ordered new lightbulbs from them, as well as this summer I had to order a new ballast from them, after mine blew out. The ballast was a very old type of ballast, but thankfully, the company had them stocked.