Hi there, well I would recommend not to take that path. ESP's spam filters are really good at spotting "undesired email". which is basically what you'll send if you acquire a database and on tops of that, why would someone open an email he/she is not even expecting to receive? I suggest that you do it yourself, or hire an agency, and build that database. That will certainly give you a better open rate and ROI.
I didn't find the right solution from the Internet.