One thing I will mention Phil is that people have been claiming for years that fish in general are more likely to freak out in bowfront tanks. It has something to do with the shape and the way they view everything from the inside out that has a fun-house effect. I am not sure how much of this is true but I will say that I personally had a bowfront and didn't notice any of this odd behavior.
I will also say that I believe all lighting is heading towards LED's. I would only recommend non-led's when someone is trying to achieve something specific, like planted tank and or reef tank where the lights play huge factors.
Other than that, led's are now dimmable, you can change the color spectrum, and discus on their own do not care too much what light you place above them. There is the exception of way too much light. I once put a double T5HO fixture above my discus tank to see how they would like it and they hated it.
You have to play it by ear.