PHP Classified system

I am looking for someone to design a website for me. It is a classified system that will allow anonymous users to look for items based on zip, city, state, and country. The users will be able to post ad's to sell items, post ad's if they are looking to buy items or they will be able to answer ad's that other users have posted looking to buy or sell items for the fee of $.99. The ad's will be very simple with no pictures or long item descriptions. The user must select if they are buying or selling, zip, city, state and country. If they are buying they will only need to say what they are looking for, how much they are needing, and how much they are wanting for pay for the item. They will also need to include either a email address or phone number and this information will be hidden until the user answering the ad pays the $.99 to view the contact information. If they are selling they will need to include what they are selling, how much they are selling, how much they are looking to sell for and a contact method, either phone or email which will be hidden until the $.99 is paid to view the contact information. The payment must be processed via paypal or ccbill before the contact information can be viewed. Also all ad's will need to auto expire after 3 days and there will be to be an indicator on the ad displaying when they expire. There will need to be a simple admin panel for manual removal of ad's as well.