A sidenote is this stirring Youtube of France's all nuclear submarine force. Youtube mainly features the Rubis class-AMETHYSTE rebuilt, Saphir SSN. Saphir displaces 2,400 tonnes (surfaced), crew 70, powered by a 48 MW reactor, 60 day mission endurance only limited by food. New Rubis-AMETHYSTEs are no longer built with French DCNS due to launch the first Barracuda SSN replacement by 2017. Initial picture above is the Le Terrible SSBN. The Youtube mainly kicks in at 45 seconds, with Saphir interior action at 4 minutes 30 seconds.
There have been many media reports announcing the Shortfin Barracuda. This may be the most detailed. All the future submarine contenders, Japan, France and Germany, are putting forward designs with varying degrees of newness. This means none are precisely "off-the-shelf" not even Japan's.
The article indicates "The preferred bidder is expected to be announced in the first quarter of 2016." If, as is likely, the preferred bidder is Japan the announcement would probably be after the next Australian Election. This is because a win by Japan, meaning "build in Japan", would be a very unpopular decision with voters - especially those in Western Australia, South Australia, Victoria and New South Wales. So if the Election is in March 2016 the final announcement of Japan would be made around April 2016 or later.
naval-technology.com, July 16, 2015 reports http://www.naval-technology.com/news/newsdcns-offers-shortfin-barracuda-australia-future-submarine-programme-4624492
"DCNS offers Shortfin Barracuda for Australia’s future submarine programme