Customize Site / Plugin in Wordpress

Dears, I am developing a website that aggregates listings of clinical recovery dependent chemical. (example: [login to view URL]) I want to have a directory that owners of clinics enroll their companies to others to find these companies to perform treatments. I want to use the tool and found a wordpress plugin that has its functions in basically 80% of what I need. The plugin is this: [login to view URL] (demo version of the plugin) I need to customize the plugin + implementation of the PSD layout (psd will deliver the entire 3 pages I will speak below) I will mention some major customizations you'll need to perform this plugin: - Add filter to search for: states and cities - Include User field to have the option to find a clinical closest to him, entering your zip code and is shown clinics near him. So the User has these 2 ways to find a clinic: filter region and closeness. Another function that I want to add is to show along with the list of search results a map with all the clinics related to the search result. (See picture draft listing page) On the details page of the ad does not have many changes. But I want to add more fields with information about the announcement panel. Example: The owner of the clinic must select details of your property to make the announcement via check box. - Private rooms - Allowed - Etc. I have other small details to be made over is basically it. As I said the customization must be done in basically 3 pages. Make a comparison of how the plugin is originally:  home: [login to view URL]   - Listing: [login to view URL]   - Details page: [login to view URL] And as I leave each page: home: [login to view URL] linting: [login to view URL] details page: [login to view URL] Schedule and Payment: 1st I'll pay 30% to start. 2 When customizing whole show made me pay: 30% 3rd I definitely do layout and deliver PSD to be placed on the website (3 pages) and when everything is finalized last part I pay money: 40%