Database Driven User Uploading Website

Hello, I want to create a site similar to [login to view URL], [login to view URL] and [login to view URL] As you can see these sites allows users to sign up and upload photos and text to a database, in a self publishing [login to view URL] then overlays their image on top of an image (ie. polaroid) (we have the design and look that we want)...We are looking for the back-end to be created. Must be with a MySQL Database. Key features that we need for the site: *Auto re-size of all images so that uploaded images are 250 x 250 px, so anything over that would be sliced and centered, check out how [login to view URL] does it... * We need to have a back end to login to and view posts that are pending to be approved, in order to edit them if there are typing errors or links that don't work, etc. * We would need different categories (such as art, fashion, music, etc.) We will let you know the categories. When the user would upload a photo, they would check what categories apply to their post, and there would be a button for "categories" with a drop down of each category * Site needs to be integrated with paypal to allow users to buy their posts.... Possibly a way so that they could by more posts on credit(similar to [login to view URL]), and then sign in with their username and be able to post. Thanks for your bids, we need this site relatively soon.... We can talk about more details when we start to choose the right person for this job. Look forward to hearing from you!