Easy to use firewall and invisible proxy?

[Alan Dayley]

Recomendations sought: Easy to use firewall and invisible proxy.

I have friends and family that want a firewall and invisible proxy
with content filtering as a gateway on their Internet connection.  I
know some of the usual suspects like IPCop[1] with Copfilter[2].
Dan's Guardian[3] is also nice for content filtering but does not
always behave well with Copfilter.

So, rather than continue my late night search, I thought I'd ask here
about possible solutions.  There must be some out there already, such
as those used in schools and the like.  Does anyone have some
recommendations?

Alan

[1]http://www.ipcop.org
[2]http://www.copfilter.org
[3]http://dansguardian.org