Customise existing Wordpress plugins or develop new ones

[login to view URL] Im looking for developer who is capable of customising existing plugins or developing a new plugin to complete the following. The plugin is required to list many different items and users. The items are endless and the information required for each item is very different. For this reason, Ive created five main subjects. The user must select one subject for every item listing. Depending on the subject selected, a form must automatically generate with fields which are required to be completed. These subjects are: (Automotive, Location, Unique Item, Forna and Flora) Each subject requires its own listing form and fields. (These fields must be fully customisable by the admin user in the backend. (Order of preference, hidden fields, custom fields, etc) The Process a user would follow when listing an item for the first time. ( not signed) Listing an Item (Must be fully customisable in the backend by admin user) The user must complete basic information fields regarding the item being listed. A popup then requires the user to sign up or login via email or social networks (view listing process at reference site [login to view URL]) Once signed in, the user is taken to the user Dashboard where all other information regarding the item being listed. Each subject would require different information. Once logged in the user then continues adding the listing in his dashboard. Adding images, videos, descriptions, listing information, filtering tags, location, address, pricing, description, booking calendar, amenities, listings, overview, etc. (view site reference) Its very important that Users are part of this plugin. The admin user will need to search for items and users who are own or who are responsible for the items listed. It is important for the admin user to know the following: Who does the item belong too? Where is the item located? When was the item, listed, updated, last used, etc What can the item be used for? How must is the item? Who is responsible for the item (does it belong to the owner or an agent) How much notice does the user require before the item can be used? If the existing plugin is going to be user and modified, updates on the plugin must be disabled.