I am planning a trip from NJ top WY. Once in MO i pland to start retracing the Oregon trail as much as possible off road on a 2005 1200GS. I need advice on route planning on my PC to then dowload my routes and waypoints on a GPS unit (dont have one yet but leaning towards Garmin Zumoo 665 or 660). Any advice? Anyone familiar with the oregon trail?