I am planning a long tour with an improvised route for which I would like to build a new set of wheels to ride out on. I had originally planned on building some 27" wheels because they would be the original size for my frame and would like to do a vintage style build. I also like the idea of having larger wheels even if it's less than a cm in diameter. Though I guess what has me on the fence is not being able to find a decent 27" tire in who-knows-where when I need to replace one or both. I have checked and my brakes do have enough reach to accommodate 700s and a guy at a LBS said seemed to think it's a no-brainer. I've ridden mostly 700c but still restoring this bike with a stout set of alloy 27s seems right on. Any thoughts would help . . does this seem worthwhile or would it be foolish to hit the road with these and invest in a dying standard?