This is what I have so far. It is a functional solution, a quite nice one actually. This is what I am using for a 1000 mile trip through Colorado backcountry that covers 90,000 feet of vertical climb/descent so I will give everyone a report after that, I start Monday.
Two things I still want to do but will have to wait are send it to Liquipel to get waterproofed and make a sunshade out of Kydex.
I am open to suggestions to make it even better but right now I am in about $300 total and I am much happier than with the Zumo 665 I bought originally.
Edit to add: I have also thought about buying a package to allow my iPhone to be a wifi hotspot and feed the Nexus. That would give me a little more flexability if my route changed. For now I will rely on Starbucks and Panera bread for free wifi.