I like them all, and in this order:
Stone and
Rocky are tied, then
Rocco. I wouldn't use them, because it literally reminds me of "rock". I'd rather use a name that describes a certain rock. Not Brick though...its cool, but too rough. I'd use
Flint! I love that name. I also like the spelling Rocko.
Name These Characters 4 (ongoing)
https://www.behindthename.com/bb/game/5345395