I am dying to know- what is this PSU for? 
I was thinking of making a transistor curve tracer, just as a fun learning project. I was inspired by
https://www.instructables.com/id/Transistor-Curve-Tracer/ but primarily wanted more symmetric handling of N and P channel transistors, as well as ideally higher current capability.
As such I thought a split rail would make things much easier for me, and that got me searching for rail splitters.
Now, gotten side-tracked by virtual ground circuits I didn't get much further thinking about the actual tracer. The main idea was to use a push-pull stage controlled by an opamp (referenced by a DAC) to provide a controlled collector current.
Having thought a bit more about my goal I imagine I have two options that might be better than full-blown virtual split rails:
- use push-pull MOSFETs and a charge pump to provide a negative supply for the controlling opamp
- use push-pull BJTs, and another opamp to adjust for the offset created by Vce(sat) when trying to pull the collector low when testing P-channel transistors
Anyway, thanks again for all the replies, they were very helpful and informative.