What kind of tango music are you interested in? There are the classic dance tunes, which everyone knows, but there is also There is a tradition of Tango song, which isn't well known outside of Argentina, but which often is accompanied by some very good guitar music--I don't know much about this music(except that I love it) but I have a few recordings, and here are a couple people that I do know that often featured guitar: Mercedes Simone, who was generally accompanied by her husband, guitarist Pablo Garcia--Rosita Quiroga played guitar--her song "A Media Luz" is a classic--

These woman were classic singers who recorded in the 20's-50's, but there is a very active contemporary scene as well, I just don't know anything about it--