Also, specific people assigned to grill, and very careful safety precautions- this is a lot of grill space- I suggest you talk to them about doing meatballs for meatball sandwiches instead of burgers- safer (no burns), less costly, can be made ahead, and much easier serving.

Not knowing the age or number of the kids, I will give you amounts for 120 adults, you can cut back about 10 if there are 15 or more children under 12.

Baked Beans, 5 #10 cans, 4 if not bean eaters. Some meatless (1 crockpot?) for any vegetarians

Potato Salad, 4 gallons, about 40 pounds potatoes
Pasta salad, 7 pounds dry pasta to start, can make 2 days ahead, pasta al dente

Chips, 8 pounds potato or 10 pounds corn, 1 pint dip or salsa per pound, consider moving to appetizer arrangement

7 layer lettuce Salad, do 2 1/4 times the recipe on this page, can do day ahead:
www.ellenskitchen.com/bigpots/plan/salads1100.html

punch- 6 gallons, add 6 gallons sweet iced tea and 2 unsweetened

Get good rolls. See the sandwich planning page for advice on lettuce, tom, ketchup, etc.

Look at the fruit tray page and veggie tray page and add these for 100 to the chips for minimum appetizer service