Have no idea about the amps stuff for the electric outlets , just using what an electrician told me to use after I had him here several years ago to swap out my "split buss" electrical main panel. I think that was the term. It had no main shut-off and was always hot.
Made me nervous when I had to replace a faulty water heater circuit breaker before I had the panel upgraded. I wore rubber boots. Two pairs of thick rubber gloves, stood on a board and said my prayers when I did that circuit breaker swap out.
The new outlets he told me to use seem pretty quality -- and of course cost $4.50 a pop. They seem to be more "rubberized" sort of material instead of the brittle plastic of the contractor-installed original outlets.
I originally asked the electrician how to remove the wires from the "spring catches" without breaking apart the old outlet. He just ignored my question and gave me an empty outlet package and told to replace them with "this kind."
FYI, your old split buss panel didn't have "a" main breaker, it had several main breakers including the one you changed. The main wires in your new panel are still live regardless if the breaker being on or off.