I have the Garmin 60csx, but if you want it for road and trail as well, the Oregon series is much better. Not to mention the fact that the GPSMap series (60,76, etc) do not handle multiple maps on the same sim card well at all. The higher end Oregon series with more internal memory will allow you to rename the mapsets to 3 seperate file names that the GPS will recognize (gmapsupp, gmapprom and another I forget) which basically means you'll be able to go into the setup and pick which map you want to use...
In order to switch maps on the 76 and 60, you need separate sim cards or you'll be doing it manually via computer before you head out on the road.