Diagram of most of the future TKMS-HDW 216. Note the space for a Vertical Multi Purpose Lock (VMPL) or two behind the sail. There is also a Horizontal Multi Purpose Lock (HMPL) (the thick tube) in the torpedo section. The VMPL and HMPL will allow the Australian Navy to quickly change and release equipment for specific missions. (Diagram courtesy TKMS).
The submarine selection is a difficult choice. But Australia should keep its powder dry and get the best deal from vendors, by keeping them guessing.
While it is a pretty safe bet that Australia will not buy SSNs it is best to be agnostic on the SSK options - balancing the boats that are partially built (Soryu and Shortfin) with what is a design (216) but not built.
Resistance against China's South China Sea militancy must be countered by political and, if necessary, strategic means.
Julian Kerr has written an excellent article on the Australian Strategic Policy Institute's (ASPI's) website The Strategist, September 8, 2015 http://www.aspistrategist.org.au/the-sea-1000-contenders-the-germans-part-2/ :
"The SEA 1000 contenders: the Germans (part 2)
Germany’s bid for the SEA 1000 Future Submarine project could reasonably be described as coming from a safe pair of hands.