Thorn Nomad S+S, Trek 520 - 2007 (out on loan), and a crap Repco MTB
The Caribou claims "Components can be found anywhere in the world" yet it is equipped with Disk brakes, 700c (presta) wheels and tyres, and STI gear/brakes and a non-tapered square bottom bracket/crankset...
I'm just going to run the disc on the front. I figure that is the only place it is really worth it. I can lock up the rear wheel with normal brakes anyway, so I can't see the point to undermining the spokes, carrying the weight, or dealing with any hassles just to do what I can already do. I am probably going to run cantis up front, or conceivably Vs, also. I don't entirely buy the idea of building a heavy touring bike to tandem standards, but I am a believer in 3 brake redundancy. What is good enough for 2 fat fudds I don't know, is good enough for me.
I should add that there are those who do not believe in discs on the front fork of touring bikes under any circumstance. Apparently they can pop the wheel. Presumably some of the same people who don't put liability tabs on their drops, or use sufficiently retentive hube designs, or secondary brakes. Some smart people, though, like Thorn. Just be aware that there are issues that need to be designed around for this to be safe.