I live in the alps, where it's very rainy and quite mountainous too. As an American ex-pat, one of the things I discovered when I moved here is that my choices are far more limited than they are in the states. I can still get Trek, Specialized, Scott, and Cannondale, but none of the lesser known brands. Even with the big brands, I can't get every model. They don't sell the Trek Portland here, for example, but at least with Cannondale I can get European models which I couldn't buy in the states. The model names are often different so one has to be careful about that. You mentioned Trek and Cannondale, what other brands can you buy there?

I have 2 main commuting bikes. A 2008 Trek 7.7FX and a 1999 Cannondale T700 (touring) which has had most of its parts replaced by Shimano XT. The 7.7 is an Al frame with carbon fork and stays (the 7.9 is the fully carbon model). I thought about getting disc brakes for it, but it would cost about 250 euros for the conversion, whereas I can get 4 new v-brake pads for 10 euros. So, I'm sticking with the v-brakes. They work well enough in the rain and snow, and it only takes a minute to wipe the rims after a wet ride. They're very easy to adjust too.

If you're going more than 15km each way, I would not recommend a flat-bar bike. I wish I had known that before I bought the Trek. Aside from that, it's been a great bike for commuting.