It depends on how "into" the hobby you are.
If you plan to spend $1000 on corals for that tank I would invest in a light meter. One that measures kelvin, par, and LUX. If you are "really" into perfection this will tell you where to place certain types of corals in your tank for ideal conditions with the lighting you have. It will also tell you if the lighting map most lights have is accurate or not, and it will tell you when to replace your bulbs because you will see the change in your lighting conditions. (bulbs need to be replaced BEFORE they burn out, as the values change over time with those kind of lights)
I will add a meter cost 1/4th the cost of Maxspect 320 watt 15000k that you thinking of buying... And is a good investment, because if you buy a 900 dollar light you can return it right away if it is not the values you wanted, without waiting weeks or months finding out watching corals. If you have that kind of money, you can afford to be sure.
I never used them for aquariums myself before, but I am new to hobby. I have used a few different types when I was in college though for various reasons.