Please consider adding to the menu, you need 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 is needed for each 100 guests.

Now on to your dinner menu:

fried chicken, 1 piece per person
baked chicken, 1 piece per person, but consider doing this in a sauce or gravy or tomato gravy, as it tends to be dry when held on the buffet
rice, 16 pounds dry
Gravy??? 1 cup per 4
rice and broccoli casserole, 4 pounds dry rice, 10 pounds cheese, each of 2 cream soups (mushroom and celery?) and about 4 pounds chopped celery and 12 pounds chopped broccoli per each 100
green beans with potatoes, 40 pounds green beans, 10 pounds potatoes
rolls 25-28 pounds
butter 5 pounds

Consider adding a fruit trim such as a spiced peach or apple ring for each person, for color and flavor.