If you two have any serious intentions of getting involved in a serious physical altercation, the last thing you want to do is publicize it or talk about it.
Keep it quiet, private, and just do it.
If you want to have an unbiased bystander (that you feel you can trust) videotape the fight, do it, and then wait til the fight is over to see what direction this whole thing goes.
You have much more to lose than you do to gain. It's not like you are pros in a ring fighting for money and a title. I can tell you from personal experience that this whole thing can get much uglier than anticipated.
Quiet down, swap phone numbers, and take care of business. Leave us out of it until it's over.
Actions, not words.