Classified website

I need to have a classified website that allows visitor to offer products/ services, properties, job, .... the web admin should be able to confirm the advs and be able to delete entries; on the other hand, services receiver can select the desired offered product/ service There should be some space for banner advertisement where the web admin only can control. That's why it is important for this website to drive in as much as possible visitors so that large companies would be interested to place banner adv. within the website. (It is important that key tags are identified in a smart way so that it would appear first in google and other search engines. the website should ask for registration. The website is expected to be simular to [login to view URL] If the selected provider (freelancer done it well, he would win another deal to build a dynamic website for a business company.