Project: peer to peer solution (airbnb for example)

I’ve been looking for weeks now, trying all themes and templates (especially on wpmu and envato) but I cannot find a solution.

I want to create a site with two types of users: the registered users that has a profile page and can add information such as his house, or his car to share or stuff he wants to sell. And the other type of user is a guest looking at the listings and can manage favorites, or messages to the owner of item.

The idea is a bit like airbnb but I want to be able to have a good starting point to customise it (rather than starting from zero).

Any advice?