If you're going to ride in the Pacific Northwest, look at the dropouts. Many 'cross and touring frames are remarkably similar, except that some 'cross frames have horizontal rear dropouts (Surly Crosscheck, for one). This can be an issue with clearance getting the wheel out when you have fenders (highly recommended for the PNW).
OTOH, the Surly LHT has an extended top tube to go along with its vertical dropouts. Note frame weights are within a few ounces for comparable 'cross and touring models.
Best advice I can give is test ride a lot, if you can find models to test ride, and pick the one you like best. You'll probably be riding it long after the tour is over. If you can't find a touring bike to ride, work with a good bike shop that will help get you set up right on the fit. Despite "pick the one you like best" advice, there's not a whole lot of difference between different models.