How can my son do tertiary study if we move to Oz?

My husband is applying for a teaching job in SA. I lived and worked/paid taxes/had medicare in Sydney for 2 1/2 yrs in 1991-1993. My eldest son is now 15 1/2 and half way through our yr 11. I read that kiwis can study at Aus. tertiary institutions for domestic fees but not get studet loans. I don't want our moving to Oz to disadvantage him. Trying to find out if we can make that the case. Any suggestions?