I've used a garmin emap gps receiver often in the past and imported routes into google earth. Worked easily and well. Have used it to log path of a plane too, and had a 3d route in google earth.
What is the model number?
Any half-way decent GPS receiver that can record a track of where you've been and that has a means of getting it on to a computer will work.
I've got a Garmin Geko 201
and have logged tracks through the USA, Australia, UK and from Helsinki to Hong Kong by train.
You can download the track data from the GPS using the free EasyGPS
program and the requisite cable of course.
About the only thing you need to check on is the number of points the track log can store (eg. the Geko has 10,000 points). A low number of points, (my previous GPS had a max of 768), and the track log starts overwriting itself.
However, before spending big on a proper GPS unit when all you want to do is log your location and get the track into Google Maps/Earth, you may want to check this
out since you're in the same country
Ooppss, forgot the bit about you wanting to load maps on it - oh well, couple it up with a cheap netbook, (eg. Acer Aspire One), and use it for the mapping part.