Ohhh....nice synths! I haven't played much with the K1 series (I own a K4 myself) but the TX81Z is nice. Also works nicely with MIDI guitars. I enjoyed FM programming on that.

I found an open source universal editor/librarian called JSynthLib. The only caveat is that it's a Java app. If you don't mind that, then it might work for you. I haven't tried it extensively yet but I will soon.

http://www.jsynthlib.org/