You can put multiple PQ's into a GSAK database to get good overlaping without getting cache duplicates (as it just updates any caches already in that database), select your centre point (home or a certain cache) and distance (if you have more caches than your GPS can take in the database) and once you are happy, send them to your GPS

I know with my Oregon, I can use POI (Points Of Interest) and get loads of caches onto my GPS from GSAK but these are handled outside the Geocaching function (effectively Waypoints with information) but is great if you are travelling and need more than the max. 2000 caches (on an Oregon 300).