On the C&O, particularly in rainy season, I'd want the widest tires that could fit my bike. Can you cram some 37s in there on the Saga? On the road, 28 might work at your weight, and if it seems a bit rough, try some 32s.

Unfortunately, by the time I need new tires, the ones I bought last time aren't made any more, so I'm not much help. Continental Contacts seem to last forever, or until you screw the tire up trying to get those tight things off the rim to repair a flat. Specialized Armadillo Nimbus wore out after 4,400 miles (pretty spectacular longevity in my case), but they felt heavy and less responsive than some others. Schwalbe Marathons are pretty decent, except for the flat I got in one last week. I'm taking a break from Panaracer Paselas and Vittoria Randonneurs because of some quality issues I ran into.