classified ads themes or plugins

Sorry if this is in the wrong place. No offense intended to anyone. I am not asking to have this built I am asking if anybody knows of any existing themes or plugins, not for them to make me one or sell me one. I don't want to break any rules here.

Specs required for the site;

Single Item classifieds site (e.g cars)
Sellers can be verified (little tick like Twitter, ebay power seller etc)
Ads vary in price (e.g featured ads vs. normal, number of pics, link to seller website)
Sellers can have a profile page (will be businesses as sellers so their logo, website, items for sale come up)
Awesome backend CMS where I can play god with the website ( remove ads, verify sellers, set ad prices, change search fields)
Has to look good, ( featured ads taking front page)

There are other thing I'm looking for but if it has all these it most likely will have the others.

This is a classifieds site for car wheels, so could a car website be modified to change the search forms and the ad forms. For example could I change 'fuel type' to 'wheel size', or 'number of seats' to 'number of studs'.

Is this is the right place?

I have found one called called classifiedengine. It seem Ok but isn't single item orientated and seems more c2c rather than b2c which I would prefer.

Could a real estate one be modded to do the job? I have found a few good looking ones