I would just get the new Deore crank with the trekking ring ratio 48-36-26, swap the 26 out for a 24, and call it good. steel rings on 2 or all 3 out of the box.
the newer higher end mountain cranks from shimano all use their new carbon/ally rings which are both expensive and goofy overkill for a touring bike IMO.
I've always like the sugino cranks but the new external BB stuff is much easier to install and take cranks off of bike. i think its a big step up. a rider on a global scaled trip could carry an extra BB for those cranks, they weigh less than a fart. or, overnighted in the mail for little cost as they are under a pound.
i've got frames that, once the threads were chased, allowed the BB cups to be installed by hand except for the final tightening. a rider could replace them on the side of the road with a rock, a belt, and a swiss army knife.