If you are touring in remote places, 27 x 11/4 is easier to find in department stores. If you are going to places where local bicycle shops are prominent, then go with the 700c tires.
In any case, pick up GOOD tires. Don't settle for the cheaper ones (under $20 US). I bought some 27 inch that were supposed to be "touring" tires, and had blowouts from the bead side of the tire. They apparently did not fit my rim correctly, and may have been manufactured with too much stretch. Since I got the good tires (after confronting the LBS with the problem), I have had no problems.
John
Last edited by John C. Ratliff; 07-04-05 at 09:41 AM.