Need info about your services

Hello,

I am currently researching options for creating a communications/input strategy for a local workforce development initiative. I use pbwiki for several personal endeavors, but I'd like to more about what you offer in a business setting.

What we need is a website landing page that serves 3 different types of users:=
Public use: serves as a basic information portal for all residents in the 16 county area that we serve (i.e., what is our organization? what do we do? what do we plan to do?). We want these public viewers to be able to leave comments on blogged materials, but not to add content.
Stakeholder use/content creation: the webpage needs to have wiki tool(s) to be able to support a widespread group of stakeholders (ideally around 1,000 people) in solving problems, adding and sharing documents, and creating and maintaining conversations. These would be users who would need a login ID.
Private use: the management group of this initiative will be reading the information that public viewers leave as comments and, more importantly, the documents and discussions that Stakeholders create, in order to make decisions for the initiative. These users would have editing controls.

Our goal is to have 1,000 stakeholders adding input (uploading best practices documents, studies, reports; creating discussion threads). We will not get 1,000 stakeholder users at first, but we need a robust capacity to inexpensively support a LOT of authors--if being an author means being able to upload documents, create discussions, and comment on others' discussions.

With such a set up, what would the user fees be?

thanks,