Duck eggs don't ship well at all. Can you look around on Facebook or Craigslist or a Hatchery and see if you can get some duck eggs locally?
You shouldn't have to monitor the incubator constantly. Just put it in a temperature controlled room and calibrate at least 2 thermometers to make sure everything is good.
I am in the middle of a hatch and we had to turn on our air conditioner yesterday. It's really messing with my temps in my incubators. When this hatch is done I have to calibrate everything again with the new room temps changed.