Do you have homebrew channel. Look it up on google and theres someto g called letter bomb or something that you put on a sd card. Once thats all done you can install openbor and access from homebrew channel.
Unfortunately, I don't have a Wii, so I can't help you in that regard, but there's something i want to ask though, did you check out the readme for the OpenBOR builds? There's a readme with the directory structure for all ports in there.
Try the older games from early 2000s the engine and scripts keep on evolving but i dont remember the last version that even worked on wii i have an older version of openbor for my xmen mod but most newer mods use the most current build of openbor which I believe is not updated for systems