Take a look at automated install using pxe. That way you can install all clients identical with a short command on each client. Some scripting is of course necessary to define the kickstart scripts. Several good tutorials on this topic are available. Below is the a link to the centos intro on this.
http://www.centos.org/docs/5/html/Installation_Guide-en-US/ch-kickstart2.htm...
Thomas,
I do use PXE install, however, in this case it takes upwards of 2 hours plus for each box to install CentOS and all my "other" items.
With disk duplication I can copy 11 disks in 30 minutes.
jerry