Smoked sausage for 80

I am cooking for a party of 80. I am doing the following:

1.Pulled pork sandwiches with sauce
2.Smoked sausage bites
3.Potato salad
4.Green beans
5.Mini cinnamon rolls

My question is, how many pounds of sausage should I need? This is the first time I am doing the sausage, so new territory for me.

Thanks and smoke on!