Building a Contact List: Strategies for Finding Mobile Numbers

Hi all, I'm looking to build a list of contacts of where i know the company name and the address of their facility location. The problem is my personas aren't really on LinkedIn. Therefore i would need it to scrape the web for staff by providing a full name and job title of all those that work there at that facility location and then use the number enrichment to find mobile numbers. Or i could just create a list and use a service like LeadMagic to find those numbers. Any thoughts/suggestions on how i could accomplish this?