It doesn't really matter which you do first - just don't try to do both at the same time
Personally I would move the database to a new SQL server first, and then upgrade ePO, but that's just me.
Thank you for your reply
Why do you suggest that?
Purely from a performance perspective. Most people move the DB to a more powerful SQL server, so moving it first means that the upgrade process - which can be quite intensive - runs on the more powerful server and so completes more quickly.
Just my opinion
Makes sense... Thank you!