I have no idea how you're supposed to get the Japanese versions, but I'll trust you. And it's English version, not versions as the first short was only released in Japan. (I wish I could find and buy the 3D and 4D short somewhere)
By the way, could you expand Serebii.net's manga section to Pokémon mangas that aren't Pokémon Adventures. If Coronis doesn't feel like working with other Pokémon mangas than Pokémon Adventures, you could post a thread in the forum's manga section and ask for help. I'm sure someone would be willing to do it.