Biggest problem with rim brakes is finding decent quality rim brake rims now. Choices are getting limited in wider sizes, Rhynolite XL is what I got last, and that was scratching around. The TRP Spykes work pretty good with Avid Speed Dial Black OPs levers, but the stock pads I got with mine are junk, Koolstops went straight on after trying to get the stock pads to work. Mind you, the brakes were out of China, so some kind of OEM excess stock so maybe not the best pads. Around USD$85 for two with shipping, mounts and 180mm discs.
And yeah, I wouldn't go on a 12 month trip on an exotic material like bamboo...