Here is the question I have that hopefully is not too general of a question.

I have a network with approximately 25 PC's, 3 servers and 25 IP cameras. I have a firewall already on the network and it works fine for what I need, but my client is asking me if there is a way to put a Proxy server on the network to monitor where his employees are going when they surf the Internet. He is not wanting to block them (at least not thru the Proxy server), but he wants to make sure that they arent going to sites that would compromise the networked PCs. I have looked at TMG and it is a little more than what I want. I hesitate adding another firewall to the system because of the security cameras that are presently on the network (IP Cameras). I just want to put a policy in AD that would make certain Users (or Computers) use a Proxy server.
Any suggestions on a good proxy server are welcome.

Thank you