Content managed website for sale of anything in south africa

We want a website like this one : junkmail.co.za. Please visit this website and see what the site does. You can place adverts for anything. The adverts are free and also paid advert for business's or services. We would like to be able to administer what adverts need to be paid for and which are free when it comes to services of business adverts. We would like people to be able to sell items free. So 3 sections, items for sale or swop, business related (jobs,etc) and then we want to ad other whole sections to the site, like Hire section, when people want to advertise items for hire ? or companies want to advertise themseleves as hiring business's. So, Buy, Sell, Hire ! W want this to be scalable and SEO done aswell so when people need something that we have listed, and they google, they find us neaqr the top. We await some information please.