Looked at doing UK ATPL and it is pretty longwinded.
If you have over 1500 hours command on a jet A/C over 30,000kg you can get away with just doing Air Leg and a licence skills test. If not you need to do all 14 exams and do a licence skills test on an aircraft that requires an ATPL.
I can not be sure but I think that if you have an Aussie ATPL they will convert it to a CPL. Maybe you can get a job with that but I think most commercial operators want a frozen ATPL.
Heard a rumour that some of the requirements may be relaxed but that was nearly 2 years ago and nothing's changed that I am aware.
As a suggestion write to Bristol Aviation, they do a great correspondance course and I am sure they will help you get the info. Also there is a lot of info on the CAA website.
Good luck, its a big world out there, and Australia is a very small fish bowl. A real eye opener once you get out and you will probably have a much quicker career progression.