Purpletank,
The main question(s) you need to ask is "do I have a British passport, is dad a Brit, is Mum a Brit? are any of my grandparents British? who can I marry?" Without the right of abode/passport then the chances of working in Britain are very small.
As I understand by your post you have yet to gain an Aus ATPL. For a "foreigner" to turn up without turbine time and airline experience then the wait for a good job will be long.
So, assuming you get the right of abode sorted.
To summarise my previous posts you will have to do the following.
Class one medical at Gatwick. Between 189 pounds (if you have +500 hours) or 400 pounds.
Groundschool for the ATPL. Min of 350 hours face to face, normally 650 hours or Distance Learning.
Approx cost 4,000 pounds. Usual time, 6 months min full time. (Note, cost of food,rent etc not included)
Exam fees. 718 pounds for the 14 exams. (Note, fees do not include resits or reschedules)
IR again. Sky's the limit. 10-14,000 pounds.
MCC course 2-4,000 pounds.
Then you will have a CPL/IR with ATPL credits. Aka a "frozen" ATPL.
Yep, it sounds harsh, expensive and very unfair. It probably is however, this is the current state of play in the UK.
BTW $A1 = 35 pence on Sat 5 Jan. Now look at those figures again...