Create a website with user functionality very similar to existing services

Our project will require a website to be built with specific functionality. We need to create a website that has a similar idea to these existing websites [login to view URL] [login to view URL] - The website must allow users to create a free account & profile with details for their pets. - Users must be able to select an area and be able to select from pre loaded contacts to which notifications will be sent to. - A way to accept payment from users should they want to use premium features. - Integration with social media, automated emails and possibly sms text messages sent upon an alert been created. - Vendor accounts & profiles must be able to be created for organisations / shelters who need to create and update their own listings for found animals they may have found. They must be able to manage these multiple listings from their own account. Additional detail regarding functionality will be further discussed with Freelancers. We would prefer to build this on Wordpress as we are familiar with this platform but we are open to suggestions & understand that another platform may be better suited. We expect that all code will be cleanly commented & indented so that we can easily understand and work on the back end in the future. We also require that any project work undertaken for us remains solely our property. We will be providing our own graphic and design material, you as the developer can work with us and use place holding images during the build process. Please give as much detail as possible in your proposal: How will you perform this task? What platform / languages would you use and why? The time estimated in hours for project? Please include a breakdown of your project steps, milestones and cost. PLEASE INCLUDE THE ABOVE DETAILS IN YOUR PROPOSAL - DO NOT SEND GENERIC SPAM PROPOSALS!!! Thank you.