Wordpress Classifieds Plugin System

I'm looking for someone who is 100% familiar with the internals of Wordpress in order to effectively craft, design and build a very specific Plugin Module that supports turning any Wordpress Site into either a total Classifieds Ads site, or that will on a more simple level allow someone to add Classified Ads functions to their existing Wordpress theme. The plugin on the whole should be respectful of other Wordpress Plugins and will need to have the following features: -- Users can either be required to register or can optionally be allowed to place ads. Registration requires Verification. -- Administration Features will allow the WP Admin to setup Categories, Sub Categories (Multiple layers deep). -- Includes a Dashboard extension to show listing progress -- Options for Payed Listing and Free Listings, or a Combination of Both (payment providers include: Paypal, -- Inclusion of Search Functions and Filtering based on variety of key criteria -- Ability to customize the look and feel of a listing form (fields and data which can be searchable). -- Ability for users to login and Make New Classified Ads, Edit Existing Listings, Delete their Listings -- Ability for users to Subscribe to "New Listings" -- Ability to add social sharing of Classified Listings (Facebook, Twitter, YouTube, Pintrest, Etc.) -- Ability to add maintain a separate library of Images and Media that correspond with the Listings -- Extensive Use of Shortcodes in order to add -- Ability to change up the listing views (Grid Format, Item Listing, etc) -- Full Search Capabilities and associated result pages for these. In short we need to capture a hybrid of all the features provided by AWPCP (Another Wordpress Classifieds Plugin) as well as OSClass both should be reviewed by the freelancer and fully understood from start to finish. No features should be left unanswered and we want this plugin to be far superior to any others. This is NOT a small project, and will require significant coding, testing and the expertise to handle the overall architecture that is in full support of Wordpress without damaging or conflicting with a Wordpress installation. Samples of Wordpress Related plugin projects are required. We are looking for an expert that knows how to write well structured