I could do this one as a fantasy experiment but that would be just that. So I will go with the reality of what could be put together here in/for such a scenario.

The rifle, a Remington 7615 with a 1.5-5x Leupold illuminated or (one of the Trijicons in a similar range but that uses the no battery illumination) along with a bunch of 10 round Magpuls. I would add the Mesa Leo stock adaptor and tube with a Magpul CTR. The Remington is as accurate as needed for both hunting and self-protection, it is available, legal and .223 is one of the most common rounds used out here so in addition to what I would own for it there is ample opportunity to scrounge.

For a sidearm it would be a Glock 17A (A for Australia which = a little more barrel to meet our minimum length requirements). All the reasons one would generally own a Glock. It is the handgun I am most familiar with. In a pinch you can also scrounge G22 magazines (the most common Govt issue handgun here) and run them in the 17. Familiarity with the 17 also means that a scrounged 22 is not a big ask to operate. I must also say that this is a tie with an unlikely contender, my 686. The .38/357 is the most commonly used handgun round here still, you have two different rounds available to use and the revolver is plenty reliable.

Finally a pack rifle, well that would have to be my Brno Mod 2 (CZ). It has been shortened to 16 inches and is topped with a 4x Leupold, it is more accurate than I and will happily put food on the table all day long. If I were to make one modification it would be to replace the timber stock with a factory CZ composite one.