Seeing as it's EXACTLY 287 people,
you decide if you want 3, 4 or 5 oz serving size.
If it's 3 oz, then you will need 861 oz. of finished product.
Since you lose about HALF of the cold weight, you need
107.625 pounds of cold meat, for 3 oz servings.
13 shoulders.
If it's 4 oz serving size, you need , you need
1138 finished ozs. This is 143.5 cold pounds of meat.
Could be 18 shoulders.
Add another 40 pounds cold for 5 oz servings. 23 Shoulders.
You got a lot on your hands!
I'd cook more, and charge alot.