For god's sake don't get creative with spellings. It's McKenzie. To do otherwise is to condemn your child to a lifetime of having a name that screams "my parents and I are uneducated." Harsh, yes, but also truthful. Always imagine how your kid's name will look at the top of a résumé for a highly competitive position. Makenzie? Not so much.
Hahahaha!! I honestly can't remember ever seeing this name written, but if there is a traditional way it's probably worth considering. That said, my baby is going to be Zakaria. It's the arab spelling, but certainly not common here. DH is Moroccan and has insisted on this spelling/name. I do worry a tiny bit because of the above point.