Hi Chris,
I'd strongly recommend taking a look at using Jenkins. I am using it for a similar workflow and it works great. It was pretty straightforward to setup. I have a build step to pull the latest version of the project from source control, followed by a step that launches test execute from the command line. Jenkins distributes the test runs around available nodes and scheduling is straightforward. I especially like how easy it is to manage our Jenkins instance with regards to doing upgrades, backups, and managing nodes. Tip: Use the Java (JNLP) web start Jenkins slave agent for launching GUI tests on your nodes.
