PHP/MySQL developer: migrate 4 legacy sites to new server + ongoing maintenance

I have 4 custom websites built several years ago in PHP and SQL. They are complex and running smoothly. My developer is retiring, so I need someone to: 1. Migrate all 4 sites to a new server by December 20, with no data loss and minimal downtime. 2. Maintain the code afterward: small fixes and tasks as they come up, on an ongoing basis. Please include in your proposal: - Legacy PHP migrations you have done (what versions, and what broke) - Your experience moving MySQL/MariaDB databases - Your hourly rate, and whether you would take a monthly retainer for ongoing work - Your availability starting this week Generic proposals will be skipped. I am looking for someone reliable for the long term. I will share server access in stages, starting with one site, after an NDA is signed.