Garmin GPS etrex does everything you need, waterproof damage proof 12hr battry life, backlight handlebar mounts available, only the X series will actually download maps, but are useless in the sun as they have a colour screen and turns invisable, Go to Garmins website, they start at about £120 and go upto £450, then you can buy the TOPO softwear if you want to go all posh, but again thatrs only for the X series.
I use the Garmin Etrex for walking, biking , caving, finding climbing routes,
It tells you milage, min accent max accent, altitude, min speed, max speed, ave speed, digital compass, constantly giving you a 10 figure grid refefrence, which is acurate down to a meter, you can save route plot routes, then use it as single waypoints or if you on your bike you can use it as a full route, 250 waypoints can be plotted i think, and it works with merorymap, so you can plot you ride in 3d on the pc at home then just click a button and it will download it straight to your Garmin Etrex, and thes the cheapest one you can buy.
The more fancy ones are ok if you go sailiung and hang gliding and want stupid amounts of information.
All the new ones can be used in 95% of Europe if not 100% now.
DONT BUY A GEKO, if you want the next one up from a Etrex go for the GPS60, here is the link to them
http://www.garmin.com/uk/products/outdo ... handhelds/