The success of your wedding photos depends more on your eye than your equipment. Nevertheless, weddings provide a variety of technical challenges.
Here is a photo showing the absolute minimum I take to a wedding: two camera bodies (each containing two freshly charged batteries), three lenses, three flash units, tripod and remote shutter releases (cable and infrared), plus extra batteries for the flashes, flash modifiers, and of course lots of SD card storage. (Missing from the shot: stands to hold one or two of the flashes.) I use Sony gear but you can easily match this with gear made by Pentax, Canon, or Nikon.
I actually shoot with two cameras, at least during the ceremony. The rest of the wedding, I may use just one but I have the other one handy if I need it. Stuff breaks. For pros, it’s tantamount to malpractice not to bring backup equipment. But you’re not a pro, so can you get away with less? Yes, maybe, if you like living dangerously.