My tips to you as a prolific purchaser and custom script writer is to set yourself apart by doing what the others don't do. There are many elements to this fetish and the more you include the more successful you'll be. Here is a list of hard to find elements in a single production:
Regular looking women (milfs, mom bods, matures, non-model types) It helps regular guys project their own wives and gfs into the scenario.
Nudity (believe it or not guys like seeing naked women lol. so nude fight; start clothed and strip to nude; or skimpy clothes with loser stripped nude
Pubic Hair (doesn't need to be full bush but the 40+ year old fan tend to have this old school classic catfight preference. These are the guys with money who buy)
Verbal Submissions (worst thing is a fight that ends in a draw followed closely by a time limit. Hearing one combatant scream her submission is $)
Punishment and Posing (loser on back posed on, face sat, eating pussy, blowing the winner's boyfriend, more the better)
What I described here will be the best selling catfight video of all time. Hope you have a big budget lol.