I use a Sony Alpha 9 and an Alpha 7 III. These are 2 top-of-the-range cameras that allow each photo to be recorded on 2 different memory cards. A welcome security to avoid any worry of data loss.
A good camera is nothing without a good lens. I mainly use a 35mm f1.4 Zeiss and a 135mm f1.8 Sony G Master for all the pictures of the day. In my bag I also have a 24mm f1.4 G Master for evening pictures and a 55mm f1.8 Zeiss f1.8 if needed.
THE REST OF MY GEAR
I wear a harness that allows me to have both of my cameras with me at all times from the preparations to the dance floor. For this one I use Cobra Flashes so that I don't depend only on the available lights of the evening.