I know a bike shop owner who rolls on a Rohloff Karate Monkey with Big Apples which is a veeery nice ride. I think he runs discs but if you want to go with racks v brakes are better anyway. disc-specific racks like the karate monkey would need due to the seatstay mounted disc tab are a baaad idea for touring. Also consider an older Fargo frameset if you can find one; the older models had canti studs and if you get a frameset you can go with whatever bars you like.