My experiences with both human bipeds, and cats convince me that both are simply too dangerous to have in close quarters. People will turn on you out of the blue, and cats shit in your hat.
...or shoes depending on how vindictive they feel that day.
All in all the solitary life seems better.
A pet brick or medium sized rock is worth considering. Not only are these guys low maintenance companions, but you can throw them at cats or people should the need arise.
At mostly no harm to your granite pet.