Comment by ckz
You might take a look around for it. They made two original versions, the 1000 and the 5000. The 1000s are pretty hard to find nowadays (seems a lot of early adopters went for the higher memory spec).
Some folks in the community even have upgraded PalmCards (the replaceable CPU board in these) that run PalmOS 5 now, hack the display to show more bits, etc.
Can you link to the Palm OS 5 PalmCards? That seems like brain surgery.