You'll be fine with those programs. No conflicts or slowdown. I use all of them except K9.
SpywareBlaster doesn't need to be running in the background. You just update it every couple of weeks, enable protection and then close it down.
You could do with a realtime anti-spyware program, as SpywareBlaster only offers limited protection.
Ad-Aware Anniversary Edition or
MalwareBytes (free versions) would fit in well with your other programs.