Hello,
I've also thought about it before, but I haven't really pursued it much due to lack of time. Unfortunately, I can't tell you if the transmission will fit. As far as I know, the 180 model only came with a Tiptronic transmission?
What you almost certainly need is the corresponding motor controller.
And what comes next after the modification is a visit to the TÜV (German technical inspection agency)! They have to approve all these 'changes.' At least, that's what I had to do with a Polo a few years ago. In that case, it was a 'downgrade' from 60 to 50 horsepower *laugh*, but that was quite a while ago...
I think I won't be making any major modifications to my AFB A6 anymore, and I'll probably sell it next year... assuming it doesn't completely fall apart by then.
Perhaps there are other AKN or AFB members here who know more details about your conversion project.
Regards,
DENNIS.