I'm surprised that the original gps app won't work with miopocket.
I mostly followed the linux based Nextar hackery and, as I recall, there was something non-standard about the gps that made running a third party app difficult. They did get debian running on it ok. Unfortunately, I didn't save anything from the wiki when it was around.
The gps app you have looks different than mine, but still the same family. Try it for a while, I didn't like it either at first, but after living with it for a year, now I find Garmin and Magellan ridiculous. My next gps will either be TomTom or Nextar.