I just looked and here's some info "dedicated area for anchoring a Rohloff hub OEM2 axle plate" Surly Troll Troll | Bikes | Surly Bikes
"or run an internal geared hub" Surly Karate Monkey Karate Monkey | Bikes | Surly Bikes

"or Rohloff setups if you choose" Salsa Fargo 2014 Fargo Ti | Bikes | Salsa Cycles
EDIT: Whoops, I linked to the Titanium frame but the other ones are a lot less expensive.

This is just an example of what's available at Niagaracycle (one of the many sites I've ordered from): Shimano Nexus 8 speed hub http://www.niagaracycle.com/categori...hub-36h-silver (just saw some Handspun complete wheels as well).