175 pieces fried chicken, way too much. 100 pieces plenty. Use the money to fill out some of the other items.
21 lbs boneless baked ham, OK
2 #10 sauerkraut and 20 lbs kielbasa, OK. I like a #10 of sliced apples and some caraway seeds in this dish.

Nacho bar
32 oz guac -skip, this is less than a tablespoon each, and will run out early, then people will miss it. You would need at least 7 pounds.
5 lbs taco meat I use 16 pounds ground meat to make hot dog/nacho chili for 100 people:
www.ellenskitchen.com/forum/messages/43504.html
2 bags of nacho cheese, 1 bag is 100 servings, OK
other fixings, use the taco/potato bar page for amounts for other toppings. At least 3 quarts of sliced jalapenos.
1 pound chips per 10

Baked beans 2 #10 cans - usual for 100 people is 4, have a crock pot of meatless for the vegetarians in the crowd. Consider doing black beans or borracho beans instead, which could be used on both the nachos and the meats.

6.75 lbs of au gratin potatoes. Very very short. I do 35 pounds per 100. Save these for your recovery day!

Do a simple green salad, using the plan for 100 salad section, it includes info on dressings.

Possible addition, a fruit tray, see the fruit tray page.