Asterisk PBX running as voice ad system (telepersonals)

We are looking for a VOICE ad system using Asterisk opensource PBX(Preferably writtin in PHP so we can integrate the voice ads into our website easily) The system needs to allow callers to make an account, leave a voice ad, call back later and change the voice ad using an account number and PIN all by a touch tone phone. Callers need to be able to browse all existing ads using a touch tone phone and all ads would be recorded as WAV files so that we can port them over to a website so online visitors can listed to voice ads as well (We will do this part of the system as long as the voice ads are in WAV format) The voice ads would not go into the system immediatly, we would need a small admin that allowed us to approve the voice ads as we plan to do billing (charge a fee per month for each voice ad) all billing will be done manually at first when we call back the advertiser. System should log the phone number if possible using call display if the phone number is available. Anyone with a simular system already made or a asterisk professional that is confident they could do this should bid. Our budget will be for up to 3000.00 but we would prefer to purchase an already developed simular system for less that has been tested and is realitivly bug free.