I also built up an LHT for the same purpose, but with a flat bar with bar ends. Parts list is the first post in this thread:
http://wereldfietser.nl/phpbb/viewtopic.php?f=8&t=14163 , pictures of the result are a bit further in the thread:
http://wereldfietser.nl/phpbb/viewto...131775#p131775.
And a shot during a short trip to France:
Changes I'd make to your build:
Crankset: Sugino XD with square taper BB (Shimano BB-UN55); the square taper should last longer than an external BB (will replace the cranks I have now with the Sugino once they're worn)
Rims: Exal SP19 or Rigida Sputnik 36h
Front derailleur: Deore, or is there a good reason for Sora?
26" LHT: 26" wheels are more robust than 28" versions and will allow you to mount wider tyres which are more robust too and offer more cushioning protecting the rest of your bike and yourself against vibrations
I'd also add a Tubus Cargo rear rack.
I second the v-brakes and Brooks. I choose to get LX instead of Deore hubs on my build, but am not sure how big the difference is. New XT hubs would be less ideal than LX for serious touring (oversized Alu hub instead of steel, smaller bearings).