IRL, I'd use Jane because I like it, Jean because it's a family name or Joanna to honour a Joanna and a Joan. But I wouldn't use all of them! And I wouldn't use a Jane + -a invention at all.
I prefer Janelle; the pronunciation is obvious, which helps.
I like Janet: cheerful and friendly. I think I prefer it to Jane, but only just. A lot would depend on the rhythm with the ln.
Jane Rosamond Helen
Jean Susannah Esme
Janet Elinor Dinah