The water is pretty murky in the Amazon and tributaries in which discus are native, so I am dubious on the need for an expensive light fixture for discus health. Unless, you have a planted tank, I think you guys are overdoing it. Discus do not love bright light.
This is what I use. Can can adjust the color temperature and has some interesting presets. The only thing it is lacking that I wish it had is a ramp up timer.
https://www.amazon.com/Fluval-Aquask...aquarium+light
Ramp up and, more so down, would be awesome! In my opinion with Discus, a deal breaker on lighting. My cheap lights don't have that.
Have a read of that article about Redox, it's pretty interesting. You'll see that it's not the brightness of the light, as much as the wavelengths that are important, and they can help with the `actual water chemistry`, which is unseen. Of course, they can help with photosynthesis as well if you have a few plants, you don't need a heavily planted tank to have that in mind. I'm not trying to argue or anything, the OP clearly wants bang for the buck. But it's interesting to consider, and I didn't have anyone bringing up these things when I chose lighting, which I would have appreciated in hindsight.