Saw this while the thread was dead, Wiiware's translation patch got updated to allow for Wi-fi rescues. Not sure how you get it working on emulator though.
https://projectpokemon.org/home/files/file/5781-pok%C3%A9mon-mystery-dungeon-wiiware-english-fan-translations/https://pokewii.net/You can also see people's rescue requests on this site apparently
https://rescue.pokewii.net/I was planning on trying this game out soon, what's the best version of it to try?