Hi and welcome to GMAT Club!
First of all congrats.
Second, nothing is impossible... but some things require a lot of work.
My suggestion would be that if you are looking to be outside of the immediate school influence you try to target the most well known and prestigious program such as IE. They have the largest program by size and best-known by reputation. Of course there are some niches such as fashion industry and SDA Bocconi.
Luckily there are easy ways to secure Australian work visa for the US citizens. Europe is a bit trickier but you will get a work permit automatically after graduating for a year or two. Generally when you graduate in Spain and look for a job in an English-speaking country, it is all recruiting on your own off campus. It is you connecting with people via linked in, going thorugh alum databases and networking, networking, networking. Things will be uncomfortable - you will have to ask people to help and you will be vulnerable but that's how it works in those situations.
Another option is often to start somewhere (e.g. Amazon in Seattle or Facebook in Bay Area) and then transfer to another office as an expat - usually that pays better and provides more options (you can usually do that a year or two after you start - tech firms provide good mobility). For consulting, pay in Europe is pretty subpar. Not sure about Australia but my guess is it is about the same. Of course quality of life is different and there are different priorities and all of that...
So, IE would be my choice probably
-BB