Not to toot my own horn too much, but there's an accordion tango UT available I made not long ago you might be interested in. It's nothing spectacular (UT system still quite buggy & limited) but until PG either those UT issues addressed or decides there's a market for addinga more varied line of the tango concept, I guess that's all there is.
oh, and of course you have my +1 for the suggestion, I love tango!