Hi Giorgio,
did you ever thought about the possibility to use DeepFaceLab (https://github.com/iperov/DeepFaceLab)? This is a tool/software that swaps faces in videos.
IF you would book 1) a non-porn-girl with a beautiful face (and recording her face in different emotions) and 2) a porn-girl (with a mediocre face but a perfect-body) THEN you could create a video with a girl who has a perfect body and a perfect face.
Limitiations of the software could be bypassed if the video director (i.e. you) make sure the porn-girl's face is never partly-hidden and mostly frontal. Also a ponytail for both girls' hair would be recommended.
I believe, if this is done seriously and the video is professionally recorded, then the outcome is nearly perfect.
Examples can be found:
https://mrdeepfakes.com/
These examples use faces and videos not especially created for this task. Still, the result is sometimes already (very) good.