Craigslist and alibaba type website

I need to get a website being developed in the similer lines as Craigslist and Alibaba.com. I need to get this done in ASP.NET 2.0/3.0beta using Windows Communication Foundation / Windows Workflow foundation and the latest technologies of Windows .net framework 3.0 if possible. The system should be totally configurable with xml config files and sitemaps. We are advanced techy guys in .NET and expect quality work in .NET. If you think you can deliver this quality please respond with the lowest possible. If you work on this project, u are more likely guided and will be learning and working with the latest/cutting edge technologies of microsoft. You will also get guidance from experts in Microsoft technologies.