You can also buy this from Alibaba - just the real thing, not the LCD flat panels. (the real ones are 10-20cm deep). I got a few two winters ago, and they are amazing for dark and gloomy Polish winters.
That's awesome, but the most powerful one is 9000 lumens from a 1200x600 mm panel, which is 10000 lumen/m^2. I don't think that's good enough for a proper sun effect since sunlight is 100000 lumens/m^2 and even outdoors in the shade is brighter than these devices. But it's certainly a step in the right direction and no doubt much better than natural light for you.