I really recommend reading the Australia forum in depth about this. There is a lot of information out there. From the brief things i've read it seems as if some states in Australia give higher preference to internationals from their own state for internships which usually means they get them. I think NSW was one of them, but i'm not sure.
In Ireland it seems as if your grades are high enough you'll get one and so far almost everyone who has wanted an internship got one?
Either way, be prepared not to get one from both and also in most cases you will likely not get your pick of places to do the internship.