Hi Cheaney,
We are food manufacturing facility in QLD.
Bare minimum obviously is city/state council " registered food premises" licence.
There are many certification body's like SCI-Qual, HACCP Australia etc. who can audit to their HACCP standards which are developed following Codex and can be tailor made for type of hazards being targeted.
GFSI,ISO 22000 makes your quality systems more appealing as sometimes supermarkets wouldn't accept certification body's food safety certification so either you will have to be get audited to their quality standards by auditing body of their choice or present GFSI,ISO 22000 etc.
Hope this helps.