I would just like to add a couple of things regarding the Garmin GPSmap 60-series:
Like many other devices running on batteries, the terminals (contact points) have a tendency of breaking if you're mounting the gps onto the bike using the undamped bicycle mount, esp. on a single-cylinger bike caused by vibration from the engine. You can solve this in more than one way: use a bike with more cylinders :-), run the gps from the on-board 12v system, get a proper mount (touratech/ram) or fill battery compartment with glue/foam to prevent batteries "buzzing" between the terminals.
more on the subject here:
(touratech has some nice gps-mounts, even lockable)
I'm a happy owner of the GPSmap 60CS myself, and my device reports 56MB of usable memory. Note that you need maps from Garmin bought separate. Only a basemap is included from factory.
You will probably find the 60C "good enough" only lacking the letter S (sensors): the electronic compass (only works under a set speed, like at stand still and IMO not needed) and the barometric sensor is absent. With a stable satellite lock in "3 dimensions," the gps will calculate your height anyway, within 5-6 meters margin.
The GPSmap60 is even cheaper with no color screen.
Back to the maps: you will have problems finding Garmin maps for your journey so you might just sit down in front of your computer and pinpoint positions/all your interests up front and send them to the gps as waypoints. You won't get any automatic routing this way, but since the required maps for this sort of gps travelling is non-existent anyway, it's really the best you can do. If someone knows of working Garmin maps with routing capabilities outside central Europe/North America, send me a note!
But remember: the battery terminals WILL break and Garmin won't replace your gps. Run it on (stable) 12V or fix the battery store!
And don't leave your old Michelin maps at home! Good'ol paper maps rules!
[This message has been edited by JoHS (edited 09 August 2005).]