From my perspective (at a pretty healthy 83, right now), I suggest that your attitude might be a touch unrealistic.Buying insurance to save me from the bad guy or the bad guy's family from suing me for a clean shooting?? Ha ha ha...not in this lifetime! I'm 70 years old and they best not piss me off.
It's possible that you will live at least a further 20 years (and maybe 30). But defending a civil suit following even the most righteous shooting will end up with you living those 20 or 30 years in a cardboard box on the street, needing "public assistance" to buy your bottles of Thunderbird.
Be careful what you wish for. You might get it.