hey, just to throw a wrench in your works, i would put the surly crosscheck on your list. i own a LHT and it is wonderful for touring, but i really didnt enjoy riding it for commuting. it felt slow, sluggish and not much fun. i recently got the crosscheck and think if feels a lot livelier, even though the weight difference is negligible. plus, the crosscheck can go with road or mtn. hubs, fixed or single speed and an internal gear hub which is what i am running now. the highter BB allows for more trail riding and i am confident in it's ability to tour, especially because i keep most of my weight on the front fork via lowrider.
that said, your low weight should allow a cross bike to work great for you (just makesure you can get a really comfy position on it, this is more important than anything else.)
gearing should be touring oriented, not cyclocross oriented. i run 46 36 26 crank with whatever size cassette you want with a mtb derraileur for versatility. this will give you versatility, as CX gearing will be frustratingly high on tour.