Web gateway

[mylinuxdude]

I want to build a linux based proxy server which has the following

- Anti - virus scanning of the incoming data (most important)
- User authentication
- Content filtering

I could find the guides for user authenticaion and content filtering using squid. But I could not find a decent easy guide on setting up the anti virus.

There is another scanner+proxy called havp - has anyone deployed it successfully ??

I want something like this

http://www.snapgear.com/index.cfm?skey=22