would the rand mcnally gps work? It uses NMEA.

As I understand it any GPS that can output NMEA should work. NMEA is available on most GPSs. There are a lot of NMEA fields so some GPSs will not output all of them. For example there is an NMEA field for temperature which I guess some GPSs can report. It looks like Kim has support for reporting temperature through his software (I saw a menu item for it at least), but my GPS does not report this data.

-Mike