Need Content Filtering / Virus Protection software and hardware

I have volunteered to help someone open their own internet cafe and he has sent me on a mission to find software that will keep people from accessing pornographic web pages while still being able to play the online game. Aside from that he also wants virus protection software to keep the computers clean. I was wondering if anyone knows of any good software packages that can do this and preferably one that can do both. Ideally, we are looking for something that has a server software version that can update and manage the computers definitions remotely instead of having to walk around and update each computer manually. These computers will be running Windows XP.

I have also heard of firewalls that can do some incredible stuff. If you know of any good hardware option for filtering pornography that could work too as long as its not too difficult to learn to use.  I personally don't know the specific names of any software or hardware options and just need to be pointed in the right direction.

Thanks,
Jerry