How didn't anyone mention 2 greats in both departments: Sugar Ray Robinson, stopped 1 time in 200 fights and that was by the heat. And Rocky Marciano: Never lost and fought through a lot of blood.
I tend to disagree with those who say BHop has an iron chin. It's a weird reality, but Old Man River so rarely gets hit flush that after all these years we don't know much about Bernard's chin.
Some as-yet unnamed guys with both great heart and chin, at least at their peaks: Librado Andrade Carlos Baldomir Glen Johnson