Car Portal Website (www.carsales.com.au)

Hey Guys, I need to develop a website same as [login to view URL] which is to buy/sell/rent used cars online. Please go through the given website. Should be able to offer deferent packages based on number of days advertised. The website should be able to set group discounts if someone buys more car slots. (It can be designed as a package for e.g one car slot = 5$, 3-5 cars lots =12$ something like that). The car listing page should be exactly like the given website with all the functions to perform search based on deferent parameters (price range/year range ect..) and multiple vehicle comparison facility ect. sellers should be able to manage their car list and personal info and I also need admin pages where admin can login and approve/edit/delete car listings and check the status for the car listing. I also need an article section where multiple editors can submit articles to the website and it should have a separate section in admin panel to approve edit/delete submitted articles. The featured articles will display in the main page while others will display in separate articles page grouped under deferent categories. Online payment facility can be integrated with Paypal/2CO so that as soon as user pays the amount he will instantly be able to update/add his/her car details. Website should be fully CSS based so that color scheme can be changed anytime. I prefer to have it done in ASP.Net C# but PHP also doesn't matter. This site should be built according to the latest technologies in the market where it should be able to handle high volume of simultaneous users. Bidders who has done similar projects in the past will have more chances..other details will be provided to the successful bidder.