I require a 'banner exchange' type web application.

I have been testing the waters of a new business model with a small group (about 6) existing clients, in which I created a manual banner exchange solution. On a web-server, I created a sub-directory for each client, containing the banner images of the other clients they wanted to promote. Then hacked together a small php script, for each client, that when called, would randomly select a banner image from their directory and display it. Everyone was happy! But I'm certain there is a much better way of achieving this. Now I'm wanting to roll it out to a larger audience of about 100 clients. For this I need to create a website for the clients/members to start managing themselves. The project will be completed in phases. Initial website will need to be delivered quickly. It will have limited features and it's not important to have everything automated. It will be mainly used for further market research and client feedback. Subsequent phases will be incremental, based on client feedback, my planned features (I have a substantial list), a better defined process flows and will be targeting larger and larger markets, eventually this will be a world-wide market, with an estimated user base of approx. 150,000 This will be a paid-membership site, so it's more important that it's easy to use, than looks pretty. I'm suggesting that the UI design be based on Facebook. My reasoning is that many of my users aren't computer savvy but generally they all have a Facebook account. (and hopefully Facebook would have done a lot of research into UI) But I'm very open to other suggestions. To give you a broad requirements of the first phase: Most of the clients will personally know or know of each other, so there will be no need for a full profile. Home Page/Sign Up - Simple signup page, similar to Facebook. Payment by PayPal or Cheque. All new signups require manual approval. Once logged in: * upload a single banner and delete it. Image to be resized if necessary. * select which other members they wish to promote. (simple list with check box is fine) * generates a some unique web(html, php, whatever) code that can then be used to display a banner selected randomly from the list of members the user wants to promote. The banner displays an image ONLY, no link, etc. * see how many times their banner has been served. * help section with video tutorials. Admin needs to be able to: * login as any user (to help them resolve any issues) * approve new members. * reset passwords. * see a few simple user statistics: TBA (# of banners served, # of users, etc just to get an idea of how things are going) * email notification of new sign-up Please quote for the initial website only. This will be a prototype application only. I am not expecting something highly polished or optimised for high loads or fully extendible in the future. I require it to look clean, easy to use and bug-free. I don't care what platform is used, but would prefer LAMP or Ruby on Rails. It can be built on existing CMS (Joomla, Wordpress or Drupal). Whatever is the quickest and easiest for you. Bid to include: * Deliverable Timeframe * UI and graphic design * Standard hourly rate (if there is any feature creep) As this is a prototype, if the winner successfully delivers project, they will likely be employed to complete further phases. Don't have any further documentation prepared, but please don't hesitate in asking clarifying questions.