I've been taking Argentine Tango lessons now for about 6 months, and the first thing I was taught was that the woman does not make a single move or take a single step unless the man leads it.
So a solo tango does not sound consistent with the spirit of the tango.
Nevertheless, if what you want to do is some solo dance steps to some tango music, you should be able to find someone who can choreograph it for you. I rather like the contemporary music of the Gotan Project; go to
http://www.gotanproject.com/english/anim_en.htm
and listen to their music, which I know you can purchase on Itunes.
Good luck with your idea.
Jerry