Classified Website same as gumtree.com

I am seeking an economical but well laid out SECURE online classified ads system. I need all the features/functionalities that are available in [login to view URL], with few modifications (e.g. "flat and house for rent", under "post an ad" will have only: wanted or offered. In offered, it will have, ever private or estate agent, then the location to be chosen, and the continue button that allows the visitor to fill the form in and click on the submit button). Full details will be provided to the coder. Actually, I need nearly 100% of a [login to view URL] clone, few things on the home page will look like [login to view URL], with 2 or 3 advertisement banners, but everything else will be like [login to view URL], with less options on certain categories and subcategories (specially the "post an ad" button) - that diminishes by far the work load. Please check the attached document. ## Deliverables 1- I would like visitors to be able to send ads on their friends mobile phones and email addresses, but I have got no idea about the feasability and cost, any suggestions? 2- I would also like RSS and facebook, Hi5, Myspace etc to be there as well, any suggestions? 3- I have already got the logo, but I am not quite sure about it, so need to discuss about it