Depends.

What type of touring? Fully loaded touring (i.e. tent, food, everything), is different that "Credit Card Touring" (buy food, stay in hotels), which is different than "Supported touring" (someone else shlepps your stuff about) which is different than short day-or-two touring (so-called S24O). Also, where are you going? Developed world with roads, or 3rd world/back country? The later you will more likely need a Moutain bike.

My opinions are as follows:

Mainstream (Japanese-built...except Trek and Cannondale) US touring bikes did not generally have canti-lever brakes and a full accompanyment of braze-ons until about 1984 +/-. If you are going fully loaded touring, you will need the cantilever brakes and all the attachment points you can get. Most companies went "all-in" about 1984 with touring bikes, and the industry pretty much lived off of 1-years production for about 2-3 years. By 1987, most companies were out (Cannondale, Schwinn, Miyata, Mariushi and more or less Trek, were the exceptions). The big names included:

Centurion Pro Tour
Schwinn Voyager
Lotus Odyssey
Specialized Expedition
Miyata 1000
Trek 720 or 620
Cannondale, Shogun, Nishiki, SR, Mariushi all had models but I cannot remember the names.

Any of these will do you just fine. There were differences in component spec's and some braze-ons, but they are all similar except the Cannondales are Aluminum, and the Trek 720's were rather unique in their unnusually long chainstays and Reynolds 531 tubing. These frames may ride a bit differently,and you will love the or hate them, but that is about it. The components are all old enough that you may wind up replaceing them with either the same if you like them, or newer things. (Some of the Treks used some less common French parts)

I personnally have/had a Lotus Odyssey, Expedition, Trek 620, Pre-tour, Schwinn Voyager and Myata 1000. I think the Expedition (1983, built by Miyata) and the 1000 were the best built, but I like the riding qualities of the Lotus (1984) the best. I will add that the differences are subtle, but the thing I really like about the Lotus is that it rides as well unladen as fully loaded. I will also note that the Schwinns seem to have the worst build quality/consistancy (frames). This will certainly stir up an argument here, and I am not interested in depating it. I sold them for years, and continue to work on older bikes from the frame up, and I stand by that statement, but don't want to digress from your inquiry. By 1988, Trek was down to only the 520, and it started to morph/have compromizes with other models. If you look at the 1990 520, the frame is identical (except tubing) to their new hybrids 790, and 770. I have one of these, and the trail has been increased for reasons I can only speculate. The result is that despite being able to load the front end down, the handling suffers. I will also note that my wife's 1989 Miyata 1000 is probably one of the nicest bikes I have seen and very well thought out. I have seen a similar vintage Mariushi that was of similar quality, but I never rode it, so I canot say as to how well it performs.

For credit card tours, I think canti-lever brakes are optional, as good center-pull brakes work as well with the lessor loads (I would stay away from side-pulls). The Earlier Trek 520's, Miyata 610, Schwinn Le Tour Luxe/Passage, Centurion Elite GT, etc all work very well.

For short tours, and non-go fast racing bike will do. Mid-1980's sport-touring bikes are ideal, plentiful and cheap.

Just MY opinions.