Security Programs

Because I am a senior member who read to much about protection, this may be a dumb question.

Is avast and zonealarm free a good security set as realtime protection and removal, for spyware, malware, and viruses? Of course, I will install MalwareBytes. I am just talking about prevention - to the point where I do not get infected.

Avast says they include antispyware, is this true?
I could install Windows Defender for spyware protection, but 3 programs might slow it down. So I am curious if these 2 are enough?

I am pretty sure others people are wondering this also.

Just to note, I also read this, but still want input.
http://www.windowsbbs.com/malware-virus-removal/67958-ounce-prevention-worth-pound-cure.html