Catering our daughter's wedding [duplicate]

1/2 pound to 1 pound per person is standard for US when planning meat amount; pending on the overall average guess and type of party.

For sides; figure on 2-3 gallons = 50 people

Another way to look at it; since you have so many sides.
1-1.5 pounds of food per person; total.

that is very simple: in europe we do 120 grams of meat per person (not including bone) and in the US I think it is 200 grams, festive occasion, 300 grams max per person.