Hm, I see your dilemma.
Diana's lovely - I'd give a thumbs up to that. :D
Indiana comes to mind too, but I don't know if you're into that, lol. I also recently heard of
Zuzana, which I think is really cool, though I don't know the correct pronunciation. How about
Jordana?
Susana?
Rosana?
Roxana?
Johana might even work, but that'd probably be incorrect, if I had to guess. =/