CMS Website

I am based in Sydney, Australia and am looking to have a CMS website created. Ideally I would prefer one of the following platforms: Joomla, Drupal, modx or expression engine but would consider other alternatives. The website concept is similar to Gumtree whereby users can post ads and buy/sell goods. * Sellers on the website will require log-ins. I would want to keep this as simplified as possible. * Each ad will require an embedded google map image and link to indicate the sellers location. * The ad will have hardcoded fields and also free narrative fields. * Photo upload capability required. * A small database will be required to form drop down lists for the hardcoded fields. These would ideally be used to simplify searches on the website. * The website will require a search facility as mentioned so a buyer can easily search for an ad. Orgnaisation on this site will be of utmost importance. I would also be looking to have space on the website for advertising. I would want to limit each add to a max of 100K flash with an option for a backup gif. If you are interested in the job, please respond providing a brief description of your capabilities, providing samples of your previous works and also providing a time frame of when you can start and how long it would take you to complete. Please provide your bid - good luck!