Hi mate
I'd probably stay clear of the REX cadetship as you end up getting paid squat!
Not sure if the Qantas cadetship allows for year 12 equivillancy, I remember they didn't allow this a few years back.
Either way, you will be coughing up dough for these cadetships, so you could quite easily just pay for your CPL on your own, without being locked in to a 6 or 8 year contract.
I'd suggest you just do your GFPT then PPL (maybe tack on a NVFR rating at the end), then knuckle down and get ALL your CPL theory done and concentrate on your flying.
If you can do it all full time you can get it all knocked over in a year or so, depending on factors such as weather, personal progress etc.
Your CPL theory will take about 2 months for all 7 subjects in a classroom situation.
The job market is great at the moment, so unless you can land a QF Cadetship, do it on your own.
Just my two cents.