My reason for responding to this thread was my concern, that there appeared to be genuine belief that PunkBuster support meant the end of CoD4 as we know it, nothing of course could be further from the truth.
I am sure, as you have said, that some find PunkBuster an essential part of running a CoD4 server. My post, from someone who has never added PunkBuster to a server, is intended to give assurance, that without PunkBuster, it is still possible to run successful servers.
More input maybe required from your Admins, but taking a hands on approach rather than leaving it to the machine, can give give a much better understanding of the game, for Admins and players alike.