While direct "downloads" are typically available through digital purchase on major storefronts, you can stream or buy the episodes through several official platforms:
: Allows you to buy individual episodes or the full Season 9 (which contains the Kid Buu Saga) for permanent digital download/ownership. Kid Buu Saga Episodes Download
For collectors who prefer physical ownership, the box set contains all episodes of the Kid Buu Saga. Kid Buu Saga | Ultra Dragon Ball Wiki : Offers the entire Dragon Ball Z series
: Similar to Amazon, you can purchase and download episodes or the complete final season here. How to Watch & Download Legally
: Offers the entire Dragon Ball Z series for streaming with both subbed and dubbed options.
The covers episodes 276 to 291 of the original Dragon Ball Z series. These episodes represent the final confrontation with Majin Buu and the series' epilogue. How to Watch & Download Legally