Hi ! I'm interested in your project, you want fetch tweet from a list of users, and store results in Mysql. You want a Perl script, using Net::Twitter & DBD::mysql. I can do this, I know well Perl as CPAN tester / author, and I 'm part of AUTHORS of Perl.
I've already worked with Twitter API, so fetch only new tweet will be not a problem.
Ping me for any question.
Have a good day.