I adore
Zipporah, as well as
Tzipporah. It's really the only Z name I like, aside from the trendy but beautifully Greek
Zoe. I'm pretty sure I pronounce it ZIH-por-ah, although I haven't figured out which one I prefer either.
Zora would make a fine nickname; I would use Zippy myself, just because it seems more natural to me. It's like
Vera being a nickname for
Veronica; I use the nickname
Ronnie as it feels a little more instinctive to me.