Ok other than the fact we are heading to -8F tonight Denver isn't that bad. Just make sure you have moisturizer if your skin dries easy.
Support comments that you should go with the business line of product and upgrade warranty, with your kind of travel you won't have the luxury of just grabbing someone elses computer for a day etc.
Depending on your companies standards, the benifit to a pc vs mac especially here in Denver, you can go a few steps and find a place which can do pc support, for macs, there are 2 apple stores (not bad locations overall) & compusa and not much else.
As to brands... IBM T-43 (i think the latest) are very good and appear to have a real nice wireless setup, if i understand correctly the antennae is built around the screen and picks up alot. Don't know much about the X series and the like. We use alot of T4x's.
Sony apparently has some very nice light weight small laptops, one of Exec Directors just got one, from the pc techs, the screen is small and for day in day out use not easy, but if you have a dock with external screen etc it is a very good trade off. Especially when on a plane.
Toshiba used to have quality business machines, but i havent been at a company for a few years that has them so base opinion of what others are saying.
If you have time, go to some pc stores and get a feel for the machines, check out weight, ergonomics etc, the lightest smallest laptop in the world is useless if you can't use it properly. Given a dock in both offices, i would lean towards the smaller ligher ones as it will make travel easier and your bag lighter.
Welcome to Denver when you get here!