I’ve never known anybody named Kunta. I know of two Kizzys, though – one was a woman with whom I IM’d on a now defunct message board; the other was the great-aunt of one of my oldest friends. Her real name was Keziah, as referenced upthread.
Kiz is not my RL name, btw. I never thought of Roots when I adopted it – I just wanted something short that started with the first letter of my RL first name. I got slammed for it on a message board (not the same one I mentioned above) when it was discovered that I wasn’t African American. Somebody pointed out Keziah/Kiz, and that was the end of it.