How do I deploy the same distro to about 20 machines and keep them updated?

I have about 20 machines that need a desktop. I have chosen to go with Scientific Linux (RHEL) desktop and would like to deploy the same setup to all machines. How do I do this? I have read about kickstart and rsync but I am not sure how to set it up and deploy. Possible solutions:

1. Opensource software that does linux machine management like I mentioned above.
2. Commercial software that does linux machine management like I mentioned above.
3. My own solution that I can build that does linux machine management like I mentioned above.

Any help is much appreciated!!