I prefer the Garmin user interface to the Magellan.
I would normally recommend a moving map GPSR but you may only have coverage from Garmins Mapsource WorldMap which has main roads and coastlines only.
Moving map GPSRS are great for letting you see where you are relative to towns, roads etc.
You want a robust, waterproof unit so I would not recommend the Emap. I am not too keen on the Etreks either but a few people use them. I use a GPS V.
The mount is important; forget the Garmin bicycle mounts. Tourtech make good mounts but they are pricey. Ram also make good mounts at a little cheaper price.
Batteries on a bike will vibrate and cause power off problems, so power it from the bikes 12v.
Carry a good overview paper map and compass as well.
[This message has been edited by BurnieM (edited 17 September 2003).]