Creating a map based on GPX files for your GPS and for MapSource/BaseCamp on your computer is possible with several existing programs, but it's certainly not easy to accomplish. With IMGfromGPX it's a matter of a few mouse clicks! This program can generate a map with the following features:
tracks in 8 different colors, as lines or areas;
POIs divided into different categories;
POIs are searchable; you can find them in the menu 'Points of interest' (or whatever it is named on your device);
the map is transparent, which enables you to use it simultaneously with another map.