Nice problem to have, both are excellent bikes. I've not done anything like this length of trip but there are a good number of journals by rohloff users on crazyguy on a bike (and also davidd who rode around australia and posts on here). In my view you will have a lot less minor hassles with the rohloff, no chattering gears, bent derailleurs, missed shifts, cleaning sand encrusted clusters etc. For me this is important as it is these that will happen and could wear you down. There are a very small number of folk who have had more major problems with the rohloff eg broken flanges that ultimately required the wheel to be sent to Germany. On a month long tour that could be very irritating, but if you are away for a few years then you just get to spend a week investigating the highlights of Ulam Batour and trust in Thorn/Rohloff's execllent after sales service. You do need to plan for changing sprockets and chains and make sure you have the specific tools.