If the JAA ATPL exams are valid for an AUS CPL then that would be a flexible option. Once you have your CPL with Command Instrument Rating and JAA ATPLs, converting the licence to UKJAA CPL/IR is quick and easy, you can be all done in 6 weeks - 4 for the CPL/IR, 2 for the MCC - so if the job market looks like picking up you wouldn't miss out.
In the meantime, RACWA will be able to sort out your CPL and JAA requirements, or you could distance-learn with Bristol GS and get your initial JAA medical done at Gatwick when you come over for the exams.
A.B.