networking social action ecommerce facebook community digg

I would like to have a site developed that combines the following features: Digg-type ranking of text, image uploading, user groups and ecommerce. It is a social action-type of site. I would like to use existing modules for initial development to see if the concept catches on. If it does, I will invest in greater customization (including, for example, Facebook integration). Standard themes are OK. I have drawings which show the concept (although I am flexible with the actual look and feel).