Are you looking for private tuition or a group class? and at what level are you at? also quite inportant how is your spanish?
All the really good teachers are in europe, they can earn more money there, so to the best ones here speak no english.
There are three teachrs that I would recomend all do group and private classes but all different.
My favorite is Juan Aguila, speeks no english, it has taken me three years to get him yo say mirror. He is very friendly and very much into social tango. Usually teaches with Mariela, who has a reasonable grasp of english enough for the teaching. Can be reached on 1558579624
Andreas and Geneveva, a married couple, teach a lot in Europe, now staying at home due to the birth of their twins. reasonable english. teach in a more european way. I think they have classes at Canning on a Tuesday can be contacted on 1563735788
Last but not least Roberto Canelo, probably the best technical dancer there is, his english is very poor but Valerie does the talking for him. I do not have his details to hand but if you drop me a note or just check the tango magazine.
Finnally aks your friend to watch out for Los Galesas in the milongas