I also agree with the 36h rims. I just loaded up my Surly LHT and it is really heavy. I feel bad for my rims.

As far as the disc brakes, what you said it correct, you're screwed if your brakes are totally dead, but I think you could find a bike store with traditional brakes easier than one with disc brake stuff. this might be changing, but it was certainly true a couple of years ago. Again, I don't have any experience riding through remote regions of Central asia, africa, or the middle east, so I don't know what disc brake availability is like. if anyone has experience, please tell us. I will be riding through central asia and maybe a bit of the middle east starting in march, so I will keep everyone up-to-date. It certainly does seem like a lot of the negative things related to disc brakes are being dealt with as of late (weight, rack compatibility).