I think OP should just shop opportunistically - whatever comes along at a good price. Look for the cantis, the longish chain stays and give it a shot if it fits and it's cheap.

And don't overlook the Cannondale ST models. If you want the best mix of stiffness/lightness/stability, there you go. I'm a recent convert - and I still like a lugged steel touring bike, too - but I haven't ridden one that stacks up to a C-dale in those regards. Mine fits 35mm tires w/fenders, would probably go to 45mm without.