Polo,
Since you mentioned regionals, have you considered directly contacting those regionals that take Aussies (and are familiar with training/processing someone with a non-FAA license) to see if they might be willing to take you in without an FAA license ? This won't get you the A320 type rating on the FAA ATPL but would save you a boatload of money and hassle.
Probably a long shot but it's free and easy to write and ask.
Either way, good luck.