Black Top: MT or AT ECU?

[kikin3t]

Hi everybody

I have a doubt for my hachi. I´m doing a 20v BT swap and now I have to find an ECU but there isn't a lot around here. A dude is selling an AT ECU.. and he says that is almost the same (the differences are for the AT transmission control). Is this true? what is your experience?
The engine RPM cut is different? my friend told me that the cut is given by the module.

Thanks for your help
Kike