Clam AV not a good anti-virus tool
My experience with Clam AV has not been very good at all. I have several SAMBA servers and Clam AV has failed miserably. On the other hand, I have never experienced a virus on a Linux machine. I am not sure what is your requirement to run a Linux A/V, but I would recommend that you go with a commercial product if you are that concerned.
Some products I recommend:
Sophos Antivirus Sophos - anti-virus and anti-spam software for businesses This is a top rated product in Gartner's magic anti-virus quadrant and a great deal at $40!
RAV Antivirus Desktop Panda Security - Panda Security for Linux
If you are concerned about protecting your valuable data, a little investment is probably worth it :)