Web-application project specification

We require a qualified technical writer to take a very high-level project description and write a detailed project specification for a highly-scalable web application/website. The specification will describe the site functionality in detail, UI page-flow, data-store information, along with page-by-page descriptions and basic layout mock-ups. The specification should be able to be given to a developer as a single document that provide them with a complete understanding of the project and what needs to be developed. You should have a strong understanding of web-applications, PHP and MySQL; and an understanding of massively scalable architecture is key advantage. You will be expected to think through all aspects of the project and ask appropriate questions to ensure the specification is complete. More details on the site functionality can be given to bidders via PM. To receive extra information and for your bid to be considered you must have previous specification writing experience, and you must include 2 or more example specifications that YOU have written. Bidders not including this information, either in the bid or via PM, will be ignored. Please note once a bid has been accepted you will be required to sign a confidentiality and IP ownership agreement before starting work. If the terms of the agreement are not acceptable to you the project will be canceled without payment.