For the longer distances you plan, drop bars and a slightly more forward leaning aerodynamic posture might be a bit faster, and more comfortable for your wrists, than the slightly upright posture and relatively straight bars on the Biria and some of the recommended bikes. The Jamis Aurora suggested above, or a Surly Long Haul Trucker, or another "tour bike" might be worth considering. They have a hint of road speed, plus a lot of carrying capacity. The Salsa Fargo shown above has drop bars, but personally, I wouldn't want the fat tires - they are a bit slower and a lot heavier than thinner road tires.

Here's a page with links to reviews of 4 tour bikes.
http://www.roadbikereview.com/cat/la...s_5675crx.aspx