Depending on your sides,I'd cook the three 10 lb packers.
With working men,I'd rather have a little extra than be short.
I usually toss in a couple pounds,or more, of sausage,cut into 1 inch pieces as snacks while I'm putting briskets together.
Your area produces some good ones,they are easy to cook,and even the women will eat a piece.
6-8 ounces of wood is about the size of 1/2 dozen golf balls,or a large fist.
Shouldn't be a problem.