Develop Custom WordPress Web Application

Hey guys, We need a custom "web application" built on WordPress completed in 6 weeks. I say web application in quotes because a lot of the functionality is already built into WordPress core, but we need to expand upon it and build custom functionality. The main requirements I would have of a developer would be that they know the WordPress core inside and out, as well as PHP. Following good coding practices and standards is a plus. As for the project itself, the main requirements would be: 1.) Order forms (allow client to order background checks, which is what we sell) 2.) User access (sign up, log in, recover password, etc.) 3.) User control (client as well as admin can change or update user's info, would also like to be able to 'tag' (or group) clients so we can use conditionals to show or hide certain thing, cancel or delete clients account) 4.) Communication (be able to email client from inside admin area, maybe a support ticket system?) 5.) File upload (allow client to upload files that show in their use profile on the front and back end, also allow admin to upload files to their account they can view) 6.) API integration with our background check software through XML (ordering reports via HTTP POST, once complete on our end they will automatically POST back to the clients account as a link to a pdf they can view ) 7.) Flexibility (we want to build upon this little by little, eventually we want to add a ton more functionality and the end goal is to turn it into a mini property managament tool) We may want to use the WordPress Admin area to be the user's client area, or we can have the user's client area in the front end. We'd be looking for your expert opinion on that. Please send examples of custom WordPress development you have completed in the past, and also don't forget to bid accordingly. We look forward to working with you on this project!