Importing phpBB3 to xF, plus migrating servers

I currently have a phpBB forum and two servers, one of which I'm going to be moving to as soon as I buy my xF license (which may be tonight). Just to make things simpler on my part, is it suggested that I move my site to the new server first, upload the phpBB3 database (it's small, just a couple of MB at the moment), and THEN install/import xenForo?

Also, if that's the order I should handle things, do I need anything besides my old database? I don't need to upload any files from phpBB3, do I?