If you guys have any suggestion other than these, please let me know.
None of the above. Literally - skip the antivirus software entirely. All of them use overhead (wasted CPU cycles) to scan for nonexistent viruses - there are NO viruses in the wild affecting Mac OS X. Yes, there are Trojans - those require you to download illegal software then provide your admin password for the install. (Hint - no antivirus software is going to prevent 'wetware' stupidity!)
The only reason to run antivirus software is to scan for Windows viruses you might inadvertently forward to other Windows users. Those will not affect Macs, and I say let the Windows users protect themselves.