Hi there,
You should pick me for your project as I am both a database and WordPress expert. I've built a number of local directory sites with in WordPress and pure PHP code from the ground up and I'm familiar with all that is required.
There will be a few tricks that will catch some freelancers importing a dataset of 1.2 million records, as well as keeping wordpress running smoothly with that many records, and I know those tricks.
I can provide advice for you to rank your sites well in google as well, I have many of my directory sites listed as the #1 result in Google for city/company type, and have a number of paying advertisers monthly - it really is a great business.
I am based in Victoria, BC, Canada, and can talk to you in English on the phone or Skype if needed to clarify specifications.
Regards,
Ken Smith