Sounds like you have done your research, but if you haven't heard of hexa-yurts, check them out! Here's a picture of different designs:
http://files.howtolivewiki.com/hexayurt.com/all_yurts_edit.j...
Thinking probably a 30' yurt for the communal building, and smaller geodesic domes for individual dwellings.
I talked to them once and it sounded like they can ship the materials in a fairly compact way. I helped put up a fairly large one - not so hard, but we needed scaffolding.