am I safe?

From: Headtheball (noanswer_at_hotmail.com)
Date: 06/29/04 

Date: Tue, 29 Jun 2004 08:06:06 +0100

I have recently completely uninstalled NAV as it was severely slowing my
startup even though I have quite a powerful system with 1gb DDRAM. Am I safe
running my network with the firewall and ZA pro running with all security
features set? Or is it essential that I have a Antivirus running? If so I
will install the free Sygate personal firewall or AVG, which of the two is
best?