Having done a few weddings myself I agree completely with Tom1956. A MF camera and a 35mm one for candids after the wedding itself. Remember you will be dealing with Bridezilla and if you are very unfortunate mother of Bridezilla. So keep things simple for your own sanity.
Check before hand where the wedding is to take place. Check the lighting, vantage spots, is flash permitted?, and other important things a week or so before the wedding.
It's a good idea to only provide proofs, so marked, until you are paid. For my second wedding the bride took my photos and then failed to pay for them.
In addition it is good to have a legally binding contract as to what you will be providing and what the members of the wedding party will NOT be doing. Particularly annoying are people like uncle Harry who will try to shadow you around with his cell phone and steal your shots. Put it in the contract that only you will be allowed to take photos during the service itself. You do not need extraneous flash when you are trying to do your job. Make sure that all attendees know of this restriction. (They will have ample opportunities at the reception.) If the bride will not agree then walk away from the job. If I sound hardnosed, you betcha. Remember as photographer you are considered beneath the caterer!
I finally decided that photographing weddings was the worst possible way to make money! Good luck, you will need it. A Xanax or two might help.