How much Ribs and Brisket???

What ever you do for ribs you must either let people know to restrict to so many bones per person or have someone serving how ever many that you figured per person or they will most likely take way more and you will run out. That said I'd figure 3 bones per person and 4 to 5oz of brisket per person if doing sandwiches.

You stated "all adults" Is the crowd going to have a large percentage of 70 year olds? I have cooked for a number of 50 year anniversary gatherings, and the problem has never been quantity of meat. The problem I have had with serving folks over age 50 has been the amount of people with "Sugar Issues" When I cook now for groups that have a high percentage of seniors----I do not sauce any of the meat, because I had so many people ask for no added sugar, no sauce. This is your family--you know the group---just keep this detail in mind.

I would figure 2 bones per person with two meats. You will probably have family members there to help serve---so that can be done if you want to be sure. One way to help insure that each person takes 2 bones is to cut the ribs into 2 bone sets---leave 2 bones barely attached without cutting all of the way thru.