Small Business Serverside Virus / Content Filtering Box

So, I am in the IT department at a smallish company (100 people). People are not running as local admins and we have semantic endpoint install on each computer, but people still manage to get infected quite regularly.

We are looking at a server side box that we can hook up to hopefully block some of these viruses. The only thing I have really found is something like this:
www.barracudanetworks. com/ns/products/web-filter-overview.php#
(no space)

I am just wondering if there are more products like this that I can compare. Also my terminology is probably wrong as I can't seem to get any good google results.

Also there is the content filter vs virus blocker. The content blocker seems to block viruses as well, but how well it does this I am not sure about.

Finally if you have any experience and want to promote / demote one of these products please do, but provide an explanation.