Thanks for all the replies.
By the sounds of things I'm probably better off going to Uni for 4 years before getting a CPL and trying to look for a job as it does sound hard trying to keep motivated to fit in uni after work.
This is a bit off topic. Let's say if Qantas did a cadetship (like the one they had before 2009) would they accept you in if you were older than 22? (I know a few people that got in who were older than 22 but they had been working as aircraft engineers and flight attendants at QF).