Joomla UK Postcode-Cities Directory

We need someone to advise on how we can have a city/postcode directory for our website running on Joomla 1. We have 10 short descriptions of our business that need to be coupled with city and postcode locations to form a city directory for our business. A similar implementation has been made at: [login to view URL] (drill down to end location to see postcodes) Please advise on how do you intend to implement this project and give past work examples. Budget is flexible and will be finalised once I have a better understanding of the complexity of work required.