craigslist type cms

Hello everybody! I need a craigslist type cms system. the idea is simple. just like craigslist I want it to be light, fast, and simple. once an ad has been posted, new php file is created (with some random name, like [login to view URL]) images saved in one folder, php files in another. there will be main php files like [login to view URL], [login to view URL], [login to view URL], etc. right now I don't know exactly how it would be, just have some ideas. so I am open to hear ideas from you. I would need for sure: search (like craigslist, title only, with pics, by category) flag as a spam function bad words filter email coder (like craigslist) poll captcha some additional features might be added. overall, I need basic functionality of craigslist and it must be capable to carry a lot of information. Also, safety is critical. I want to make it simple, yet i want it to be hard to hack. please don't try to resell me some ready scripts. I will be happy to take a look at some good scripts if you have some, however, I wont buy it from you if it is some addon to wordpress, drupal, or if you just trying to resell me something. Thank you! Best Regards, John.