Database Consolidation - Web Interface

I am the Marketing Manager for a lead generation company. We've been in business for eight years and have accumulated 100's of spreadsheets with approximately 500,000 to 750,000 contact data records (names, addresses, company name, type of system, etc.). The spreadsheets are disparate in the headings ("Zip" on one might be "Postal Code" on another). Some may have "Full Name" while others have "First Name" and "Last Name." Some might have information that might be present on that spreadsheet but not others. Some company names are disparate ("Microsoft Inc." might be "Microsoft" on a different record). The bottom line is that we would like to homogenize this data into a single database that we can then easily add to at our convenience and is web accessible. This is what we are looking for our provider to do: 1. Provide advice on whether to use MySQL, MS Access or other database platform. 2. Take all of our spreadsheets and data files and enter the data into a single database. 3. Combine data (if there are multiple records of the same entry) to get the most accurate record. 4. De-duplicate the data. 5. Create a front end web user interface for upload and download of said information: • Must have downloadable search results based on all different criteria (all fields provided) • Must have reporting of said data numbers • Must have admin login and easy user creation • Must have import and export capability • Web interface must match current web design (can provide template) • Please also provide estimate on building it on [login to view URL] app exchange 6. Provider must be accessible to communicate by telephone if needed (International providers OK, but English-speaking is a must). If you do a great job, we'll be happy to provide excellent feedback and give you more work, as necessary. Thanks for bidding and we look forward to working with you.