Kids need cheap stuff. Yellow Garmin Etrex if you want to download from a computer. If not, Garmin Geko or Magellan Explorist 100.
I Bought my Grand Kids Garmin Rino 110's they have build in radios so they can talk to each other. a etrex with a radio I got them on Ebay Brand new for $99.00. You can buy a usb cable on Ebay also in order to download Cache info. They have a good time with them.