The chances of your classmates being able to work for a 'couple of months' in one of the Services in Aus is slim to nil. Most of the Services have an extensive recruitment prosess and even with prior training, you will still need to go through all the hoops needed to go out on road. I did my initial training with guys from the UK and one from the US, all were very experienced Paramedcs from their home land but all had to jump through the hoops to get on road. There are the local policies/procedures etc to be learnt and probalby wouldn't be worth it for your mates and the Service for it to be for only a 'couple of months work'.
Don't mean to burst the bubble of your mates.
No worries. I've looked into myself and thats pretty much what everyone has told me. If I ever go down to Aus, it's for the beautiful beaches!