The most important aspect--and the reason I'm posting this message and asking for input rather than just Googling--is availability.
1) Do you want reset or !reset?
2) availability, With the posts we see from some countries, I do believe you will have to sell a kit.


BUILD a supervisor. A cheap dual opamp should do it.
Nope, A supervisor is specified output from a VERY low Vcc, an op-amp is not.

Erik