Penne Pasta
Alfredo Sauce
Marinara Sauce
Roasted zucchini, squash, mushrooms
Roasted chicken breasts and thighs
Hot Italian sausage with onions and peppers

Penne Pasta- 12 pounds per 100= 9 pounds, and I would have some for back up- you can always make pasta salad later

Alfredo Sauce
Marinara Sauce
For this group, I would do about 5 gallons. The balance is 2 of one 3 of the other, do the more of whichever one is more popular with your group.

Roasted zucchini, squash, mushrooms- 24 pounds ready to cook

Roasted chicken breasts and thighs- 1 of each per person- you will have some left, chop it up into your future pasta salad

Hot Italian sausage with onions and peppers- 1 pound sausage per 4-5 , equal weight veggies. You know whether this crowd are heavy eaters, use that to decide.