I'm starting some contract work on a small, new website for a grant-funded curricular program. Between now and when the site launches, I need to communicate with a small group of non-technical faculty stakeholders/collaborators about all the usual components of a new site: wireframe prototypes, sample graphic designs, current status of work, bugs/enhancement requests, and such. For reasons related to travel and scheduling, it'll be difficult to get everyone in the same physical space before the site launches, and I need some good tools to streamline that communication.
For these faculty, the default communication method would usually be email, but that quickly becomes unwieldy for agile development approaches. For some of what I need, I could cobble something together from Google tools, but I'm not ready to teach humanities faculty how to file bugs/enhancements into a Trac system. I'm looking for something a little cleaner and smoother. I don't have a private server, so I'll need either a hosted service or something that can run happily on a shared webhost.
My software-developer friends in industry tell me that Atlassian Confluence is a really good option for what I need. At $10/month for the hosted version with 10 users, it's cheap, but I'm reluctant to deploy something that'll be an ongoing budget expense unless it really is better than other options (i.e. less work for me). What other tools should I be considering?