ISO: Amount of Meats to purchase for 200

Hello, Hope someone can give me guidance. My daughter is getting married in 3 weeks. We are preparing all the food for the reception. We do not have sit-down meals (They would be easier!) We are planning to have chicken salad cups, Korean beef, chicken wings,meatballs, cocktail weiners, egg rolls, turkey-ham-balogna roll-up along with vegetable trays, fruit trays and other goodies. Problem: How do you know how much of each meat should be purchased? AThanks in advance for any assistance / guidance you can give. The wedding will be at 5 p.m on April 18, so any assistance will be appreaciated. Thanks