Missoula technically has an international airport, but that's only because it flies up to Canada :)

Closest airport that I would consider 'major' is Seattle, which is a solid day's drive (about 7 hours). You can get anywhere from Missoula's airport, but you'll have to stop through Minnesota, Seattle, Denver, or some other major hub. Adds a little cost, which is a bummer, but still possible, and even for someone who travels all the time like I do, it's not a deal-breaker-level inconvenience.

Amazon-wise, it's just as fast as anywhere else I've ever lived. I have a Prime account, and often receive my packages the next day.

I'll also add that the internet is some of the fastest and cheapest I've found outside of areas that already have gigabit up and running.