Thanks for the reply!
About huts, I assume that in Ecuador we will be spending most of our time in "refugio." For Peru, Bolivia and certainly the Atacama, I'm planning we'll use a shelter of our own.
And yes, I did consider the Bombshelter, but it is out of our price range. We need to keep it under $400.
Your comment about the bivy is interesting. I've been hemming and hawing about this for awhile now: why not just bring, say, the Trango 2 and my BD Winter Bivy. In a pinch, everyone can just cram into the tent for the night. Otherwise, I can stay in the bivy outside. What makes me nervous is committing to this system for four months. My standards are Alaskan, recall. What do you think?
Thanks again!