The movie, "The Odd Angry Shot" is worth a look if you can find it. Really shows Australian soliders at their best.
"The Team in Vietnam ....The Lighter Side" by Vic Pennington is a damn fine read. Details many, many (mostly extremely humorous) incidents over the course of a decade + members of the Australian Army Training Team Vietnam (AATTV or The Team) experienced while serving throughout the country.
As for books on SAS operations in Vietnam - good luck with that. Unlike many nations, the SAS takes security seriously, even 30+ years later! There are certainly a few about though, but don't expect a lot of detail about events.