I have been really into creating a custom SAD light setup ever since I moved to the Midwest. Much like @slevin, I was originally drawn in by The Lumenator and I have drawn inspiration from this recent deep dive into the topic by David Chapman.
The TLDR is that most lights for seasonal affective disorder on the market are underpowered and overpriced. If you want the good stuff, you gotta DIY it. Here's a look at the (admittedly chaotic looking) setup in my basement office.
It provides me 10,500 lux at the click of a button.* (10k lux is the minimum you want in order to stave off SAD, according to some studies)
The bulk of the bulbs were purchased about 4 years ago, and few were here when I bought my house. Flat panel LEDs are all the rage right now, but I already had these 50+ 9w LED bulbs plus all the strings, so I just re-used those when I moved into my house a few months ago. I had to buy some new hooks to hand screw into the ceiling. Those only cost a few bucks.
The biggest difference maker for me has been the giant stage light looking thing that is sitting on the desk. It looks like it's $230 now, but it was $179 when I purchased and I also had a $50 discount to soften the blow. It's a beast, I love it. It generates more lux than all the other lights combined, and it's totally manageable to have it on while you work as long as you buy a set of cheap diffuser screens to put on it.
I tried the corn cob bulbs a lot of people rave about but I didn't think their lux output was worth the price.
Oh, and I measured lux with a small light meter , but there are smartphone apps for it as well. (I noticed the apps were off by ~1000 lux compared to my meter)
The total cost of materials was roughly $500-600 over the last 4 years. It could probably be done a lot cheaper now, as lighting tech keeps improving and coming down in price. Maybe it's partly placebo, but I truly do feel more awake and energized when I spend time bathing in the lumeny goodness. It's especially helpful for overcoming the post lunch energy slump.
I'd be curious to see and hear about other people's setups!
*I say "at eye level" because what I care about is getting light into my eyes. My meter records almost 90,000 lux if I stick it right next to my giant desk light, but I don't work with my face pressed up against the lamp