Hi I tried your files but when I got to the download files it said none were there.
Have you heard of a pro team called acoustic-eidolon? They are a husband and wife team. He plays a special guitar with two necks and she plays cello. They are quite fantastic. I went with my wife to one of their concerts. You can look up their web site at
http://www.acousticeidolon.com/frameset.html
Both necks of his guitar (he calls it a Gitjo) have seven strings. One neck is tuned like a guitar and the other like a 5 string banjo with two extra strings.
I have done duets with a flute and also with another cellist, and also a vocalist but I haven`t tried one with a guitar yet.
The flute a cello really sound nice together. Keep up the good work.
Bob