The Aquia uses it's own adapter.
While the Unifit has the toilet dropping straight down into the top of it,
The Aquia adapter slides in from the front.
In addition to the adapter, two plastic blocks are screwed to the floor, and the mounting screws that you see in the picture thread into these.
The toilet is quit snug to the floor this way.
I'm not aware of adapters for the Aquia that allow a change of rough-in.
You should be able to get by with 11-1/2" or more for the rough-in.