I like
Zainab a lot. Never heard it with a nn, though. I've known a
Suzanne who preferred to be called Zanne, which is better than
Suze I suppose.
Zane ... my ex brother-in-law used to read old, second-hand cowboy stories by
Zane Grey or perhaps
Gray: I looked him up once and, far from being a cowboy, writing was his hobby and he was a dentist. So that's my association: not feminine, not interesting, wannabe butch.