It depends on if you want to pay or would like freeware. For firewalls there the free version of ZoneAlarm from click here. There's also a paid for version with some added features.
For AV theres the free version of AVG from here click here or there's avast click here
Again there are paid for versions of both. You should also install the spyware finders adaware6 from click here & spybot search & destroy from click here.