I used DOP MOD to install IOS 249 with a 80 base on IOS 250.
In DOP MOD the description for IOS 80 says (Only Used for Wii Speak)
I run the game on IOS 250.
Only problem here is that it is hit or miss with the headset. Sometimes it works and sometimes it does not. I hope that someone can use this as a starting point to get the headset working. As for now, its all i could figure out so far. The only draw back to this is that you cannot retrieve your friend requests because it says wii connect 24 is disabled when in fact i had it turned on. I hope this helps, Im having a hard time believeing i figured this out...