There is not a lot of work in Buenos Aires, although the situation is getting better.
I do know as a fact that native English speakers can find work teaching the language, and although you´d prefer not to do it, I suggest for you to reconsider it; at least as a back-up plan or starting point anyways...
Otherwise, you may want to think about bringing enough money to spend around 6 months looking for work, it is not unrealistic. Living there is not expensive, rent and food can be really affordable, having fun a little less...
I suggest that you rent a room in an apt with some young people, there are opportunities like that.
To look at classified ads for work, check out the corresponding section of the biggest newspaper in Buenos Aires:
www.clarin.com
Also, some employment agencies have branches in Buenos Aires, and they may be able to help you in your research so you have a clearer idea of where to start, I am talking about companies like Adeco, Manpower and the sort.
Kiss my city for me when you get there!