Do any considerations need to be made for OpenFire (using an MSSQL back-end on another machine) when installing an anti-virus solution?
Your speeds may be affected by your antivirus but other than that you really should have no concern as long as your processor and RAM are up to the task. If your AV comes with a built in firewall you could run into some port issues. I run Mcafee Total Protection For Small Business (http://www.mcafeeasap.com).