4 ESCs driven by the Servo library - although that won't necessarily give you stall detection (some
ESCs will have that I think, finding out is the tricky bit).
For high reliability there is the issue that typical ESCs have the same build-quality and reliability
issues of the original pump controller (cheap chinese circuitry, no decent quality standards?)
I suspect that internally the Jebao controller is just a cheap and nasty AC-DC converter, an ESC and
a microcontroller to manage controls and display.
You say they keep failing - take one apart and see what the problems are - perhaps a decent 24V
supply and bringing out the ESC control signals is all that's needed?