Correct about wire nuts. As far as I know, they're the north American standard. Based on the two options I see here, it looks like they're also the most archaic option lol
Yes, that's them. The Marettes as the other answer suggested look even more sketchier, jeez, twisting wires and calling it a day for for up to 32A?
Anyway, I've found over torqued screw blocks in my parents home that lost pressure due to slight plastic deformation of the copper wires over time and that's something you'll never find out until the connector box starts smoking 0_o