Wait, you already sold the movie to a production company without a written script or even a treatment?
Having written movie scripts, submitted them to multiple production companies, and they didn't even make it past the reader. Let alone have I never heard of a movie getting a green light based upon a pitch.
For a fight scene you would not write in every action. You simply write "and they fight." Leave the scene up to the stunt coordinator and director.
Stick with the writing aspect and stay out of the stunt coordinator and directors "business."
You don't want to take up valuable page space detailing a fight scene. You only have 98 - 110 pages maximum for a script.
The Lake Charles Martial Arts Team,
http://www.lcmartialarts.com
Edit:
Okay, let's say you have the funding and a distribution contract.
You would still be better served by researching "martial arts pressure point strikes" on the net. There are tons of videos on the net. Since you would also have suspension of belief you can write in almost anything. For instance a strike to the upper leg that causes paralysis.