You shouldn't have any trouble at all finding parts for the Trek. At 1/3 the price of the other bikes on your list (1/2 in the case of the Windsor Touring, though that's obviously another one you can't ride before buying), to me it's a no brainer - get the Trek. Of course I'm cheap, and partial to 80's Treks. Interesting that someone replaced the cantilever brakes with sidepulls, though it does look like there's enough clearance for fenders/fatter tires. Pretty easy and cheap to switch back to cantilevers if you want maximum tire and fender clearance.

Of course, if you really want a brand new bike, you should just do that. These 1980's sport/touring bikes are great commuting/touring/road workhorses though, and at a much cheaper price.