Welcome to the forum Jonx,
You can get almost all ingredients you need in Australia. Many are available from most supermarkets. Most specialist ingredients are available from most Asian stores.
You can easily get most "Patak" pastes from most supermarkets (and, certainly, from most Asian stores). They include Patak "Tikka Paste" and "Tandoori Masala paste". These are, seemingly, used in modern day BIR tikka (i.e. marinade) and tikka masala (e.g. chicken tikka masala) recipes, etc.
However, I personally prefer "Ferns" pastes (available from most Asian stores). They also supply "Tikka Paste" and "Tandoori Masala Paste".
There are several brands of "Kebab Paste". Try Benjamins or Ahmeds (available from most Asian stores).
I have only found one brand of "Kashmiri Masala Paste" (used in some tikka marinade and onion bhaji recipes) - "Ahmeds"; available from many Asian stores. If you live in Perth (Mick) then try one of the four Asian stores on High Road, Willetton (e.g Maharajah's). There are also many Asian stores (Indian and Chinese) in Northbridge.
If you live in the Eastern suburbs of Melbourne, then try Greens Road in Dandenong. Or the high street in Dandenong.
If you live elsewhere (which I know you do Jonx), then sorry, I can't help you!

But I supsect the above products are also readily available elsewhere in Australia.
Having said all of that, I believe that you are far better off making your own spice mxes and pastes. Everything, to do so, is also readily available in Australia.
The one thing that you can't get (or that I have yet to find) is vegetable ghee. I am told (by Asian store owners) that Austalia disallows it to be sold!
The other thing is coconut flour. But you can get it from health stores (at $20 a kilo!)

Hope this helps?