Chili for 150

I am a member of the local Vol. Fire dept. We are in the process of raising money for our new fire house (the old one is falling apart).
I have the job of making Chili for our Church lunch.
We are estimating about 150 people.
Chili is not the only thing we will be serving, we are planning on cornbread, salad, some type of vegetarian dish, coffee, tea and cider.
I have made sloppy Joes for 150 before but I having trouble finding a recipe for Chili for 150.
Some call for between 12-30# of ground beef for 100 servings.
I used 30# for 150 sloppy Joes, but I think than would not be enough for 150 chili servings.
Any help will be appreciated.