Some believe that K9 turned out to be the dualcore K8 chips, while others believe there was a seperate K9 design which was scrapped when they shifted to dualcore.
However, most, including myself, believe that there was never a K9 as it sounds like canine (i.e. - "dog") which AMD didn't want to be known for - for obvious reasons.
In any case, a K9 was never released.
As far as the structure of the K10 (Barcelona) - read the sticky:
http://www.tomshardware.com/forum/223161-28-collection-data