I believe a Transalp (any model) would make an ideal overland/RTW bike, although I'm not talking from personal experience of overlanding, I am on my 3 1/2 Alp, all have been utterly reliable and a hoot to ride, I can imagine few scenario's that an Alp couldn't handle that another bike could.
Honda claim just under 200kg dry for the 650, a friend has his over the weighbridge and it came in at just over 200kg (203kg I think) "wet" with a full fuel tank, crash bars and pannier rails.
Shopping around will find a new/demo for just over £4k.
Sure the 600 has a more down to earth, back to basics feel, but the 650 is still a fine tool.
Only moderate fuel consumption (47mpg) and toolbox job to get to the airfilter or adjust the preload let it down a bit.
With a few easy mods the fuel consumption can be sorted (flaming emissions regs....)
And I made/adapted a hydraulic preload adjuster for the rear shock to cure that annoyance.
Air filter access (under the tank) which I can live with.
Check out ;
techtransalp.co.uk (early days on this one)