GPS unit for backcountry skiing?

I do a lot of skiing in Vermont, and am looking for a GPS unit that I can use my route map for the forest and upload to Google Earth. This makes / models would be better? I want something that is mapping the roads, not only contain the benchmarks. recommendations?

Looking for a GPS that accepts Topo. For example, many Garmin maps card games customized to include additional data – navigation aids, Mole, and so on. Also I make sure to take AA batteries. Models more likely to use custom batteries – AA can not be beat (or AAA) if you are in the middle of nowhere and the batteries died. Always use a couple extra sets. Another interesting feature as altimeter feature – better 3D models using GPS and a barometer.