What do you mean with player we find you?
You can contact the players directly on social networks, and some of them even have their own websites with their data or their contact forms. So, contacting the players shouldn't be a big deal, and why are you looking by regions, you should be looking for tennis players and not for countries because those players travel a lot for the games and tournaments.
But as other users already mentioned, this is illegal and players could go to jail if they accept a match-fixing deal.