The question to ask at the end of the day though - and this is something only current tech crew for each airline can answer - is "Would you recommend the job as it stands today, based on what you now know about it?"
In talking to a VA FO a couple of weeks ago, he does still enjoy it, but wouldn't necessarily recommend it as a career anymore. Ever-present sim checks, time to command, medicals, and management mentality all play a part in that comment.
Another thing to consider, not just the education side of things: With those airlines mentioned, should you get be accepted into one, where could you conceivably be based, and could you afford a reasonable lifestyle on a cadet wage in that city? Rex pays their FO's around $50K for example. That's not going to come close to a decent place in Sydney. Plus car. Plus power (exxy & going up), etc.
As much as I love flying - don't we all - I am glad I gave the RAAF away and fly exclusively for fun now, when I want, where I want, in a job I actually enjoy more than flying.
Please don't take this as trying to put you off pursuing an aviation career - I say similar things to people when they ask me about driving trains for a job. And my answer is "I love it. But it is not for everyone. The roster can suck, the shiftwork can be brutal and as a result you will get bugger-all family time But even with all that, I wouldn't do anything else - flying included."