Pro Sites - clone entire site to a different domain

Hi there, I would like to clone / backup my entire Pro Sites powered website (site DB's and associated files) and move it over to a different domain name for testing purposes. We have about over a dozen paid client sites (through Pro Sites) and have it all mapped out with Domain Mapping.

I understand the process of exporting -> importing the database and files, but I'm concerned how our clients sites will behave if we delete them off our NEW TESTING server / domain name. Will it cancel their live / paid account even if they remain active on our "live" web site?

I don't even mind backing up our live site and leaving our client's information from the export... I'm just not sure which tables to leave off the export? ie. Export the entire site / settings / files but omit the sites and user tables.

Hope my question is clear, thanks!