Something important before you commit yourself to a course / country is to look at the job prospects there after you get your licence (unless you are one of the lucky few that have a job lined up on return in the UK).
Check what your realistic chances are on a job as a new commercial pilot and if you can legally work there (visa) (don’t believe the schools brochures on that but do your homework!) because it will make life much easier if you can return with not only the rating but also so time in your logbook.
I know that some schools in the USA will get you a 2 year J-1 visa what gives you the chance to get some experience, but don’t know the situation in Australia and NZ.
Good luck on whatever route you take!
Send me a pm if you want more info about the route I took.