If you are looking for the English dub of the "Final Chapters," you can officially find it on: Streams the Dragon Ball Kai (Final Chapters) series.
The first appearance of "Innocent Buu" (Fat Buu). Dragon Ball Kai 2014 (Dub) Episode 30
Available for digital purchase per episode or season. Quick Facts Saga: Majin Buu Saga If you are looking for the English dub
In (which corresponds to Episode 128 of the overall Kai series), the English dub title is "A Monster is Unleashed! The Terrible Buu!" Episode Summary Dragon Ball Kai 2014 (Dub) Episode 30
Includes the Majin Buu saga under the Dragon Ball Z Kai catalog.