Design of variable split rail power supply
I'm attempting to drive an array of piezo transducers and am
  struggling to find a good design capable of driving from around +-5V
  to +-30V at about 2A for my testing.


Piezo's are capacitive and don't care if there is DC content across their terminals or not. Just design a single-sided H bridge and if you are really worried then use a capacitor in series with your piezo, just like a push pull audio amp does with a ground referenced speaker and a single-sided supply: -