I've been aware of Handybits freeware for some time, it's all user friendly and quite effective, but in no example is it the best available, there are far better zip programs and erasers available. As to having two Anti Virus programs on a PC, from bitter experience trying it when I was a newbie, this is high on my list of things not worth doing. When Anti virus programs clash, the results can be very destructive.
If you want a backup check I'd prefer one of the on-line scans like Trend Housecall click here or Panda Activescan click here
If you still really want a second AV program, have a look at ClamWin click here as it doesn't include an on-access real-time scanner and as such is less likely to get in a frazzle with your primary AV software.
As to the virus scan integrator, because of the potential problems, I've never bothered with it. But with the proviso that two active AV scanners with real time cover is a very bad idea, at least one should have that facility disabled. Don't see why it shouldn't do what it claims.