Hi Robert,
I just came across you project and it sounded interesting, so I thought I would bid.
As I understand the file with 50K accounts would list logins/passwords, so that the script has to log on to twitter with those credentials and 'follow' the specified account. (Just as a side note, from experience I can tell you that it might not work within 1 hour. Twitter might have some sort of throttling in place, so it would block excessive requests from same IP).
Anyhow, I can make this for you, I have extensive experience with automating pretty much everything, scraping, web APIs, etc.
As you can see I don't have much in my freelancer portfolio, but that's just because when I started out here years ago, I soon found people who wanted to work fulltime with me. Now I am getting back to doing some projects here (but only interesting ones :) ).