Hey Scotty! Mate of mine is an Ambo in nsw and I considered it as a change also. He told me you need to be reasonably fit, and you do some entrance exams I think. Once your accepted you get paid to train on the job. Only downside I saw was they can post you anywhere in nsw regardless of where your family is. As he said, they put their staffing requirements ahead of your needs!
Good luck if you follow it up mate!