Fried chicken, 1 piece per person
Pulled BBQ Pork, 1 pound ready to serve per 6, with 5 large or 12 slider buns per pound
Need a vegetarian option 12-16 patties or Field Roast type vegetarian sausages
12 pounds sliced onions
2 gallons pickles

Cheesy hash brown potatoes, use the quantities discussed in the recipe at the bottom of the breakfast planning page, you need 4 roasters full

Beans, 6 gallons some meatless
Coleslaw, 5 gallons

(Also, considering green beans, yes, 8 #10 cans or 40 pounds

Also I strongly recommend an appetizer plan and here is why:

A self-catered buffet is a real challenge to the organizers, and things don't always come together as smoothly as hoped. By planning and setting up an appetizer area or "nibble table" which is ready when the guests begin to arrive, the cooks and servers have time to complete the arrangement of the dinner buffet. This is especially critical if there are children among the guests, or there is a wait before dinner, as at a wedding reception.

This does not have to be complicated. Three items, plus a punch, or two if one is alcoholic, are sufficient. Typically, include a fruit tray, a cheese tray and an attractive dip or spread; or you can go with a dinner theme such as TexMex with chips, salsas, Texas caviar and guacamole; Italian with bruschetta or antipasto; maybe shrimps or other cold seafood, if budget permits.

One appetizer service area easily serves 100 guests.