Please update the links at the Interstate Mod and Patches Area at this Website, all are down. Only mediafire links works. But the IS82 AIX file missed at mediafire, please update. Please create an events.
McAfee is a good business quality anti-virus. Theres grisoft avg and clam antivirus as free alternatives.
For a firewall its good to use a hardware based firewall / router as its one less thing for your pc to do.
Microsoft defender is good free protection against spyware.
Just bare in mind that for gaming performance its a good idea to setup weekly scans and only turn on real time scanning when your downloading and running software from the web.