That Yukon looks right for you.
As you mention, brakes in the right place, right sized frame and so on. You have the makings of a 26" Galaxy right there.
Drop-bars, quality wheels, wide range cassette and a good spread of chain rings. Cantilevers and road levers work well with heavy loads if time is taken to set them up properly. V-brake road levers are available too but I find v-brakes a bit snatchy for touring use. I found some Tektro levers which are adjustable between canti and V and can take this abruptness out (fork judder - just ask any Specialized Tricross owner)
The Yukon also has all the mounts needed, headset is 1 1/8th so you can easily go to ahead with Surly forks and stems galore.
Yep, well that's the sort of lines I was thinking along. No mounts for a rack, but clips work fine and it could share the mudguard bolts. I might have a measure up and see how the geometry compares to say a 26" Surly LHT. Do you think a fork upgrade would be worthwhile?
*Edit: Here is my 700c 'do-it-all' bike - its goes off-road quite well, commutes 30 miles a day and gets muddy during this overlong winter. It has survived winter road salt well but has literally eaten a set of 30 year old NOS Shimano brake blocks...
Gearing is absurdly wide with 34/ 28 through to 11/50!
That's really nice - in fact making me lean towards a vintage tourer instead...