32637 Need Classifieds Script

Alright what I.m se4arching is a classifieds script like [login to view URL] I need it to have some advertising space and have a engine to controle advertisers.. allow them to login check hits and what not.. has to be linked with paypal and offer clients the option to edit there post, leave msgs for sellers.. must also be easy to change the layout and look of it. I'll want someone who is already done something like this and a demo. I'm on a tight budget so no crazy offers..