Hi,

My design was almost the same. I used two MOSFETs (common drain / common source) though. Reason:
  • Better Current Handling
  • Quicker Turn-OFFs -- Because when you use diode OR-ing you loose the low going edge that turns off the MOSFETs fast

Also I used an active Op-Amp amplifier for the current signal.

The link you posted should work absolutely fine.