I am guessing the power rail requirements are;
+ -16V
+48V
+20V
If so our 1U rack mount power supply will do your job. You have a choice of kit or built.
It has two separate dual outputs and one single +48V output.
You can set one dual output to + -16V @ 3.75A per rail which I am assuming will be sufficient for the main audio.
You can set the positive side of the second output to +20V from which you can draw up to 3A . You will still have the negative side with the same specifications if you need it.
Finally you have +48V @ 500mA.
We can do the same specifications in a floor box if you prefer.
PM me if of interest.
You