The UniSA mid course will enable you to register as a midwife only. The course is designed to produce midwives not nurses and I think it is a good idea to be aware of that before you start. Different professions. I think it would be hard to do externally but still do-able. It is quite a high score to get in, I think the GPA this year was 5.83. Good luck, it's a really personal decision.