Norton AntiVirus ... That would be your best bet I would imagine. Are we talking for a remote dedicated server here or not. Im fairly certain Symantec has a server version of their A/V software, but you would have to check on that.
What's the problem with remote dedicated?
Get Symantec AntiVirus Corporate Edition - has Server Version and Client Version.
For a single server I'd suggest having Client version. Works perfect with Win2003.