I don't think there is a shortage of 26" tires. There may not be a large selection of "Touring" type 26" tires, but there are plenty of 26" tires out there that would work. When you say single track, what kind of single track? The Pangea is a great bike; however, it's not a MTB, so it's not going to carve up single track like a XC MTB.
Why the Pangea? What type of touring are you planning? I'm not trying to be nosey, but maybe I can help you decide.
Disclaimer: We own 2 Pangea Rohloff and 2 Nor'Wester Tours (now called Cascadia) bikes. The Pangeas are fairly new (since June), so we haven't had a chance to go fully loaded yet; however, we have done several overnighters with them. The Nor'Wester Tours have seen 3 European trips (Germany, Slovakia, Czech, Poland, Romania, Hungary, & Austria), many overnighters here in Florida, and thousands of commuting miles.
Have you looked at the Divide?