If you're within driving distance of an REI, you may be able to test ride a Randonee (road), Safari (mostly off-road), or Mazama (in between) bike. There are a few wrinkles in the mass-produced touring bikes available, such as the long top tube on the Surly LHT. However, pretty much all bikes pick from the same selection of groups available, so there's not a whole lot of difference between a Trek 520, LHT, or Randonee. So after you've picked out your genre from REI, pick a production bike in the color of your choice (slime green, dead leaf brown, or black). Wheels will need to be touched up, you may want to switch saddles, and you'll wear the original tires out.
The key is to get one that fits you (or your wife). REI doesn't do much to fit a bike, honestly, so if it's not a good fit there, pick out a good bike shop with a good repair capability and a great fitter, and buy the bike you choose.