Catering party on the 19th

My partner and I got asked to cater our Christmas party. They want brisket and pulled pork. Can anybody tell me how much meat we would need to smoke for approx. 50-60 guests. There will also be other side dishes like potatoe salad, cowboy beans etc.

I was thinking 40lbs brisket and 40 lbs of pork butts. (am I out of line) Im not sure how much meat I will end up with for final product.