I know the process is a pain in the butt but I have found the New Zealand Nursing Council to be much much quicker than SA. If you reg in NZ there is a Trans Mutual Recognition Act where you can get reg'd in Australia without having to provide the mountain of documents!
I was registered in NZ 2 years ago and it only took about 6 weeks inc posting documents to be registered. It has expired but I contacted them and all they require is a form to be filled in (they emailed it to me immediately) and a letter of good standing (verification )from NMC costing £43 to be sent to them to reregister. The verification can be sent to 5 nursing boards so I put SA Board address on it to.
Spoke to SA this morning and all I have to do is fill in another form, bring practicising cert from NZ and letter from manager in UK stating my qualifications and that I have worked as a nurse!! It will be $190 to register in SA but can be done at the office in Adelaide right away.
NZ are fantatsic at getting in touch via email and they seem to process applications really quick. Can't remember the cost of registering there but it seems to be quicker.
Might help some to get rego quicker!