In the Army you are going to get a lot of injuries (comes with the job), after three Afghan deployments I can tell you it is not a nice place, chances of something happening are several hundred times higher than the RAAF, food is better the RAAF, they are treated better, money is the same, they live in rooms on base during exercises not in a hole in the ground, they shower everyday not fortnightly, they work gentle men's hours and are more "relaxed" about everything.
Lot of respect for the infantry but look after yourself, one thing about defense now as soon as they are done with you it's a pat on the bum a handshake and your out the door...... With the RAAF you have a much longer "service life" and you will come out of it better at the other end.
With any defense job though the money is pretty good, try and get as many qualifications that are civilian recognized as you can, with infantry you may get a lot of weapon qualifications, some range qualifications but not a lot that transfers over to city street.
You should be able to save a fair bit, put it into silver, gold, property, shares or whatever you want but set yourself up for when you get out.....