ISOs are very large and waste a lot of space. Please download an NKit ISO to play with Dolphin or a WBFS to play on a console. If you absolutely positively need an ISO, please download an NKit ISO and convert it to ISO with NKit. The bandwidth you save will make downloads a little faster for everyone.
Wii Disc Formats
Smallest size. Works with current releases of Dolphin.
Larger size. Works with Dolphin and Wii consoles.
Largest size. Works with Dolphin and Wii consoles.