I am not familiar with four_antispyware, so I cannot comment on this.
SuperAntiSpyware does track a LOT of tracking cookies. Some people use it, but many are now using MBAM instead.
Ad_Aware is now obsolete and has been replaced with Malwarebytes (MBAM), which most of us use here.
NOTE: You cannot use anything that says "Internet Security" because it will conflict with Avast because it will contain an antivirus in it.
Spybot SD has mixed reviews. Some have had conflicts with Avast especially if using Teatimer (TT). Many have had to uninstall it because of conflicts recently, but everyone's system is different.
Spyware terminator I have heard of no complaints or conflicts.
I would recommend putting MBAM (free or Pro/paid) on your machine)
http://www.malwarebytes.org/ as a back up scanner.
You can also use add-on's in your browser(s) to improve your security with things listed in my Signature.
Also, don't forget to have a good 2-way firewall as well for improved protection.