Build a website

Hi all, I have a website, that is pretty much 80% functional. I would like to re-design it and increase the functionality, As such, we already have a very good template for the structure/functionality. Several of the requirements are: Admin and users to post videos (upload, or embed from youtube etc) and text (wiki style)/graphics. There will be 2-3 different levels of permission for the different users The website should be designed to grow to include more navigation categories and sub categories without a re-design. There should also be functionality which allows users to message eachother, follow eachother, and a feed which allows users to see other users recent activity (i.e recent posts) There should be a registration page There should be a profile page for each user as well as blog functionality There should be an area which aggregates content/links (based on rss feeds). Users should be able to create, share and adopt playlists based on the videos which exist Very strong back end CMS functionality Designer/programmer must: Have best practice i.e be familiar with latest technologies Help consult on best practice Work to firm deadlines High degree of accuracy and detail oriented Good sense of design respond very quickly to defects and bugs Will only accept a payment structure which allows us to pay a little up front, and then the bulk of it towards the end. I understand the risk for the developper, but i have had too many bad experiences with a large downpayment, for what i believe is terrible work. This is of course negotiable Only serious applications please. Please respond with a budget and timeframe for completion. Also, please send me links to websites you have completed already and a reference from the website owner. Thank you Cedric