Business Directory

We would like to create a business directory from a database of around 300,000 companies. They are currently in a database split over multiple tables (structure provided upon request).

There is a 3 level categorization (district, city, company). The companies need to be accessible under a URL like /district/city/company-name.html.

Navigation is by browsing (district->city->company) or by direct search for company name.

Obviously this should be done using Drupal functionality, preferably a node for each company so that we can use additional modules like forward, printview, rating, etc.

Please provide a quote via PM with links to similar work or description of experience.

Thanks!

-Tobias