Community Based WebSite

I am looking to design a community website that contains the features of Yahoo! Personals, Ebay, Onforce/Guru. There will also be a business section and I would like to have some myspace characteristics as well. I want to take all these services and put them together in on community based website. The administrator of the site should be able to enter the communities Zip codes that the site will service, and the site should configure itself from there. There will be profile pages for participating businesses, local news and politics, local special interest. There will also be "corners" for community professionals to write about there field of expertise, and I would like the old artles to be archived. I want businesses and groups to be able to post of to 3 upcomming events to be scrolled on the first page. I know this is a lot of stuff for one site, but the design has to be clean and uncluttered. I would also like users to have the ability to customize there front screen to suit their particular interests in the community. This will be a long onging project with lots of add ons and tweaking as we go. I will be marketing the site in my area - but like I said the software should configure itself to whatever area it is serving. Please include time frame and cost estimate of getting the first working version of the site available. Thank you