MYSQL: Need Backend List Manager for the Email Software "Sendy"

We need to be able to do some database edits via a UI that will let us do bulk edits to the database of our [login to view URL] installs. The database is straightforward and simple. For this first gig we need this: We want to be able to bulk unsubscribe people on multiple installs of sendy, so the script will need a UI that allows us to import a CSV (200k+ lines of emails we want unsubscribed) and script would scan through multiple databases and mark matching emails as unsubscribed in the databases. BUT, We are hoping to make this an ongoing project, we will need more things added into this back end platform with a UI. All will be simple database edits and bulk edits to this fairly straight forward database. And our entire budget for this is $500 and an experienced programmer could do this for us in a few days i believe. Your software has to be efficient and reliable, we have to know that it will execute the MYSQL database commands fully and on all database. I don't want a program littered with bugs and will not waste our time on someone who can not deliver working software.