Hey Sam, & welcome, sure hope we can help you here. Hmmm at 6-1 & 150 you’re not much bigger than myself and I can tell you, a liter bike is not even going to feel you on there. Before you jump on board something as big as the concours try pushing it around or putting her up on the center stand, that will quickly bring everything into perspective. Big bikes are no problem once you are moving over 20 and terrific at warp speed, but at low speed they are like a lame duck out of water, they must remain balanced 100% of the time or it will tip over and there is no muscling a 670 lb. bike once it starts in the wrong direction.
Sounds like distance is your thing so keep these on your shopping list; Full fairing, shaft drive, liquid cooled. If you can actually find a Concours cheap go for it, but with the money you save get yourself a little beater bike to learn on. If ever there was a candidate to learn on dirt that’s you, dirt technique would relate directly to riding any motorcycle without the extra 400 lbs. and costs associated with having 2 road legal bikes.