^^Perth is a beautiful city! Being English I bet it will be slightly easier in terms of visas etc.
Here is the Police Academy website for WA: Academy | Western Australia Police
You still may want to check on citizenship/residency requirements as they are sometimes stricter for law enforcement (i.e. A visa may not suffice). That website should also tell you if any skills are transferrable although I suspect you would still need to go through the WA academy.
Good luck and happy researching (you will be doing lots of it