The LHT is a good choice, but I must say that I really like the Rivendell bikes. The Atlantis takes big tyres with fenders and is tough enough for expedition touring. The smaller frames (56cm and lower) use 650b tyres and the larger frames 700c. I own a Rambouillet and a Quickbeam and I've toured on both of them, they are great for road touring where you don't expect to be going off road. You might also look at the Saluki and the
A. Homer Hilsen (weird name, interesting bike)

The thing that I love about Rivendells is that they are really comfortable and have well thought out clearances and places for racks. I also like lugs......there are plenty of good tourers out there, but there's something about riding a Riv with a Brooks saddle that feels really nice (I know I'm a retro grouch). Also I'm a big fan of the wide Nitto Noodle bars (46 or 48cm) as they open up the chest and make for easy breathing and comfort.

Buying a bike from Rivendell isn't cheap, but you'll be spending the money where it matters most, on the frame and if you get the Phil Hubs and BB cartridge, on the moving parts. Also Rivendell are very helpful and always available on the phone.

Finally whatever bike you buy I think the most critical thing in touring is what you bring along. You have to be comforatble, but you should balance that with minimizing weight. To that end I set a 25lb limit on my touring gear, with ultralight camping techniques this is doable, 1.5lbs for a tent, 1.5lbs for a sleeping bag etc. here is a link to a guy that did a self sustained tour from Vancouver to S.F. on a Rambouillet with tent, sleeping pad and sleeping bag, this is how I approach touring, if you bare in the Yukon you might need more stuff though.

http://milly.org/rambouillet/