Importing listings - Excel to phpMyDirectory

We would like to import 1.4 million listings from 2 Excel files (190MB each) into an installation of phpMyDirectory. Listings fall into approximately 95 categories which must be created. For each listing the Excel files contain 3 levels of location; the state, county and city. We require these locations to be created within phpMyDirectory and for each listing to fall into the right location (by location ID in the database) and category (category ID in the database) so visitors can easily navigate the site. Some listings within the Excel file have the address and the county name fields missing. Any experience with phpMyDirectory would be valued here. You will be given examples of a single listing, category and location which may be deleted later so you have an idea of the convention and the way data should be formatted to take a little Search Engine Optimization into consideration. Also, there are duplicate listings which will need to be removed. Payment will be made once all listings are visible on the front end.