Anna is the only spelling in use where I live.
Ana looks like a word ending: stuff associated with
Queen Victoria could be Victoriana etc.
I quite like
Anna with the English pronunciation; it's widely used by Afrikaans speakers sounding like AHnah, which I'm tired of. And a good friend has a wonderful
Anna daughter! I have personal reasons for preferring
Anne, of course, and I've used it as a mn for my daughter, so
Anna was never in consideration.