Duplicating MU Installation

We're currently running WPMU 2.7.1 and need to duplicate our installation to test plugins and upgrades. We have a dedicated server with Rackspace.

We don't need the two installations to be in sync like a true staging > production environment, but we do need the clone to be the same to make sure changes are accurate.

Does anybody in this forum provide these consulting services, or could possibly point me in the right direction?

What are common best practices for duplicating test servers?

Thanks for ANY help!