I haven't done much touring yet but I plan to this coming spring/summer. My (CX) bike has the Sora 3500 and so far I've put about 2000 miles on it. I haven't had any issues with them and they seem to be doing well. I'd imagine 105 levers are a bit more durable due to the materials they use. But even so, I think the new Soras are a good bit better than the old models. I think in general, many STI shifters can last quite a long time if treated well.

I believe all STI shifters should have the same pull amount. They all should work with calipers, cantilevers, and mini V-brakes.