Which 24" MUni do you ride right now? What cranks do you use, and are you happy with your foot position? This would influence whether you would prefer the KH or Nimbus cranks.
Dual hole cranks should really be paired with a good quick release seat post clamp, but I am a big fan.
You will probably find this thread started by George J informative. He was asking a similar question regarding unicycle choice and KH vs Nimbus etc.