If it's a firewall you might want to upgrade to the latest in the series
you are using (4.11). There may be security holes in 4.8 by now.
There are very few anti-virus packages for FreeBSD. AFAIK there are no
viruses that target FreeBSD. There are a few that target x86 hardware but
these don't propagate over the 'net.
Have a look at amavis (it's in the ports collection). I've never used it
but it's been mentioned a number of times on various lists.
Also, F-Prot (www.f-prot.com) provides an AV product for FreeBSD (NetBSD,
and OpenBSD too). They even have a mail scanner product. I used the file
scanner for a while but stopped the last time I upgraded the OS.
For simplicity, get one of the Firewall Router devices and stick your
FreeBSD system behind it. Most have a web interface to manage them. Just
make sure you get the Firewall model and not the Router with NAT model.
Unless you get lucky, the guy a Best Buy (or whereever) won't have a clue
about the differences and will not be able to help even if he thinks he is
helping. You need to do your research on this.
On FreeBSD you have a choice of IPFW, IPF, and PF. IPFW is FreeBSD only,
IPF runs on many OSes (but not Linux), and PF is a port of the OpenBSD
firewall. All are included with the FreeBSD distribution but require a
kernel recomple (it's explained in the handbook and isn't nearly as scary
as it sounds). All are about a complicated to configure/manage.
PGP KeyID: 1024D/CBC5D6BB