According to the back "Shadows of a Black Sun" It looks like CoK will not be in the core book. I never got beta but always thought the premise of the adventure was really cool is there anywhere I can get my hands on it without buying the whole beta book?

Unless FFG decides to release it in some other format, pdf or adventure module, no you will not be able to get it except in the beta book. They may leave it as perk for those who purchased the beta.