a social networking site

Hello this is a social networking site where users can 1. sign up/log in 2. create their meeting with targeted information and this creates a detailed meeting page with unique outlook 3. other users can search this meeting by keywords etc. 4. other users can apply to join 5. those users can exchange messages/chats 6. user can edit/delete their meeting etc we have graphic designs(not translated) . should w3c/xhtml validated. should be expert in php. will display detailed info upon signing of NDA. timely delivery and proficiency in english are a must. should be good in communication and follow the requirement.