Here is a table that may be of interest to you.
People may argue, but I think if you use your server for its intended purposes and manage it responsibly, antivirus software is not that critical. Even if you have it, doesn't mean you are 100% safe.
Keep you server patched, don't use it as a workstation, limit and control access to it, educate employees on (at least) basics of cyber security and enforce your company's security policies.
But of course all major vendors would have a solution if you positively need to install an AV.
i would no more run a server sans AV than I would jump out of an airplane sans chute.....AV on a server is one of those things that absolutely proves the 'better to have and not need' credo.....I recall when conficker hit a few years back, servers were dropping like flies.......
but for a server, I'd go something enterprise; probably Symantec.
EndpointProtection Small Business Edition 2013 is antivirus/antispyware, firewall, intrusion prevention and generic exploitblocking. It supports servers, workstations, and network machines. The SmallBusiness Edition also allows you to choose whether you utilize on-premisemanagement or management through the cloud.