There are 3 western made AIP-systems one is the French MESMA by DCNS, the other two are a Stirling-engine made by Kockums and fuel cells used by HDW. The French system is not already in active use while the German fuel cells are used on operational Type 212/214/Dolphin-class submarines. The Swedish solution with a Stirling-engine is in use on Gotland-class, Södermanland/Archer-class and on Japanese Soryu—class submarines.
Therefore Australia also need to ask Kockums about the complete drive train.
Btw. Kockums is owned by TKMS.
MESMA is in service with the Pakistani navy and may be adopted by India (ironically). Spain and Italy also have AIP products in development. The Spanish one will go for their S-80 subs.