OK, Ive tried to get Comodo to work .. I can get past those errors, but the on-access scanner still doesn't work, and it tells you there's a problem on startup .. though the normal scanner works.
I've tried Bitdefender, which can be installed in Peppermint with a few tweaks .. but it doesn't appear to have an on-access scanner either.
* got an on-access scanner (which stops you even accessing the eicar test virus files), but hasn't got a GUI
Theoretically I suppose you could have both AVG and Bitdeefender installed .. but IMHO you need neither unless you're running something like a file/mail server that services Windows PC's
I may test others soon, but I've had enough of putting stuff on my system that's unecessaary for now
Meanwhile, if you want instructions for AVG or Bitdefender .. just ask