What is the purpose of that research? I'm myself often searching for rural locations where I can find a spot with the open horizon on the South side from a road somewhere high in the hills/mountains, and where I can park and setup my telescope not far from the car overnight. I'm using just Google Maps features - the Terrain overlay (topo map), the Aerial view, and finaly the Street View where available.

However, in the past I've been using the Delorme Topo USA (still have it) for the similar task as well as for hiking trips planning. It has a very nice 3D visualizing dual screen feature, where you can have your topo map on one side of the screen in sync with the 3D view of it on the other side. Then, you can draw your path on either of them and see it unfolded as a profile of slopes with angles and distances. Perhaps, that's exactly what you need.

By the way, in Google Earth you can draw a path over the terrain and then right-mouse-click it on the left side bar. In the drop down menu you will see the "Show Elevation Profile" option, which you can manually navigate in sync with the map.

Upd: just discovered this overlay for Google Earth: http://ge-map-overlays.appspot.com/google-maps/terrain it resembles the Terrain feature of Google Maps, should be more suitable for terrain research than aerial imagery.