Please pardon any repetition of what's already been said.
If I could start over and buy/set up one bike for the rest of my life to tour on and use as my do everything bike, I would end up with a steel mountain or expedition touring frame and fork that fits 26" wheels with cantilever brakes. The 26" wheels are important to me because now having toured on my 700c touring bike, I'm consider setting up another 26" bike for more remote tours (ex. AK to AR). I know my current touring bike can do the trip, but 26" tires and wheels are easier to come by on this little planet of ours and I don't have the clearances to put the width tires I want on my current bike.
If budget is an issue, find an old steel mountain bike from the early 90's/late 80's that fits you decently well. The chainstays won't be long enough and their won't be mid-fork eyelets, but those problems can both be overcome. Steel racks are important because if they fail, finding someone to weld steel will be much easier than aluminum. I would chose Tubus racks because they have high load ratings, they make a rear rack that sets the panniers back farther to prevent heel strike with short chainstays and they make mounting hardware for a fork with no mid-fork eyelets.
Beyond that the things worth spending money one are, fenders, good tires (I vote for folding Schwalbe Marathon XRs), the right gearing for your needs, waterproof panniers(I'm a fan of Ortlieb back and front rollers) and good 36 spoke wheels.
If budget isn't an issue or you've done a really good job of saving your pennies, throw in a Rohloff Speedhub.
Last edited by waxy; 12-30-08 at 11:22 PM.