What's the best way to do this?

What is the best way to do the following?

I want to scrape twitter users who have retweeted or favorited a particular photo on twitter. Then I want to use a tool to be able to find out what countries each of those twitter users are from.

So I'de have a list of retweeted/favorited users and from that extract lets say those who live in the U.S onto a seperate list of twitter user IDs.

Is there any software you would recommend?

I dont know of a software, but I have friends who collect from Twitter and they prefer doing it manually, yields a much better quality. Good luck!

Manually is not very scalable. This is why I'm looking for an automated way. I've heard twitter added demographic data to twitter users, but I'm not sure if your only able to see what country your own followers are from, or whether you can see what country any user on twitter is from.