Directory Style Website

I am looking for someone that could develop a database driven site (The style of database is irrelevant to me and I'm open to suggestions). It will be similar to [login to view URL] but there will approximately 25 fixed categories to this particular subject with the ability to support a nation wide amount of companies, this will start small, in one location and grow from there. The companies that advertise with the site will have options as to their level of commitment which in turn guarantees a higher placement and the ability to show more information. I would also like the company to have the option of whether or not their customers can leave a feedback and a rating score. If they choose not to have either of these options then it doesn't show in the customer page. If they do chose feedback, we should be allowed to review or edit it before it goes live. I would also like a "back end" so that companies can be added by us and options checked to show which level they are at. We would also need to be able to add or ammend categories and other relevant site information. If possible, I would like this to be linked to some kind of automated billing system so that the database holds information about the billing cycle and reminds us when a company needs to repay. The customer side of the site needs to allow the user to register but they can also see information as a visitor. If they do register they will be allowed to check the categories of companies relevant to them so that future visits will show only these selections unless they choose more. The user should be able to use a map or postcode to select their region so that companies are shown by local relevance. There is a lot to this site and lots of ideas for many more things that can also be added. Further ideas could be.... Taking company payments (Paypal or other method). Blog page. Facebook / Twitter links. Advertising space. Please ask questions and without revealing the whole project idea, I shall answer the best I can.