I Have 3 clients running 2003 server / terminal services running norton corporate 8.1. One other client has citrix over 2003 server with NAV corp.
All works great.
Keep in mind that there's no such thing as a perfect AV scanner, you still have to be proactive about the software. Antivirus software is not a "set it and forget it" issue, just make sure you're set up correctly and keep an eye on things.
~ K.I.S.S - Don't make it any more complex than it has to be ~