We would be nearly $20 a plate. Minus linens for the tables. The amount of sides is tough because there are 4 of them. I'd roll with a minimum 13-15 racks of ribs, 70 pieces of chicken, 5lbs of beans, 6-7lbs of taters, 2 or 3 1/2 pans of casserole, 5lbs of slaw and 55-60 potato rolls. I'm assuming that you are using dinner rolls for your bread.
You will I'm sure have extra. However, I would rather have to much than to little. Just my .02
Good luck, remember to post some pics..
[B]Big Daddy's BBQ[/B]
[B]Concessions and Catering[/B]
Louisiana Grill - Whole Hog
30x72 Reverse Flow Offset
16ft Wells Cargo Mobile Kitchen
12ft Full service Mobile Kitchen