I mean, it's just my personal experience with requests. People tend not to do it unless they get paid.
Still, it wouldn't hurt to try to ask some people. I feel like personally messaging the writer with your idea and giving a proper detailed description with pictures and gifs would probably help the writer gain more interest in your request. Again, I think Decker vs. Owens (with gifs) would interest some of the writers in the celeb forum. I don't remember their names but a few write good titfights and only post in that area.
Otherwise, if you want to commission, especially with something like One Piece, you should ask Luffy316 to do that for you.