I like
Kimberly although it's a bit of an 80s bimbo name, and I prefer the spelling Kymberley nn
Kym because that's my cousin's spelling, hence it's the one I'm used to.
Kimi is ok, but a little too cute and insubstantial for me. As long as it's only Kimi when the child is young, and matures to
Kim when she's older, there's nothing wrong with it, although I prefer the more robust spelling, Kimmie.
:-)