4 butts 8lbs average= 16lbs of cooked meat or 64 1/4lb sammies
2 briskets = 15.6lbs cooked or 62.4 1/4lb sammies
17 racks x12 per x 2 bones each serving 102 servings.
or 3 bones each gives you 68 servings.
Lot O' meat though per person. Adding any sides you may do, And that's a boat load of food. I might be inclined to cut the ribs down to the 2 bones per, But that's just me.
Good luck on it.
The Only thing consistant in BBQ is--It's always the Judges Fault!