Here is the download link to the Japanese Melee save file that has every character and tournament legal stage unlocked. I may have to update the file later on just to include the random stage switch.
However, this is only usable in the Wii version of the GameCube Backup Loader. If you don't have it, you'll need to install a custom MIOS and a custom IOS 249 on your Wii, then use some kind of WAD Manager to add the GameCube Backup Loader channel.
Code:
https://drive.google.com/file/d/1N4nRhGfPvoQ-9v7VwRgqW0miffa3BgQb/view?usp=sharing