Kendra, this is a big party, requiring about 4 people in a commercial size kitchen and 12-16 out front to set up, serve, and clean up. These folks will be working during the wedding, not attending.

I never suggest fried chicken unless you are willing to purchase it ready to serve; this is difficult, even dangerous prep for this size group. There are some really good wedding chicken recipes on this site which can be made ahead, frozen, then assembled day of. And you have sauce for the potatoes.

I strongly encourage you to add 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 serves about 100 guests.

Now, about the dinner menu.

pulled pork- with chicken, 1 pound ready to serve per 5, 12 slider buns or 5 regular buns per pound. 1 pound boneless raw pork makes a pound. I recommend shoulder for this use.
onions, 5-8 pounds sliced per 100 persons
pickles 1 gallon per 100 persons

fried chicken- 1 piece per person, or wedding chicken recipe using 1 pound raw boneless per 4

With this size group you have to provide a vegetarian entree, or at least a side dish that can serve as a meatless entree.

8 gallons mashed potatoes, cutting it close, OK with the potato salad
8 gallons baked beans, OK
8 gallons cole slaw, OK maybe some left

green beans from my grandma's garden 65 pints would do, plenty

50 pounds of potato salad, at least 7 gallons. With the mashed potatoes, you might consider pasta salad instead, it's easier, you would do 12-15 pounds dry pasta as the base.

10 ten-pound cans of corn. Assuming you mean the #10 cans, that will be plenty.

2 dinner rolls per person
3 pounds butter per 100