The Texas BBQ Posse's collective mouths dropped open after seeing the Loco Coyote Grill's BBQ Po Boy being delivered to a neighboring table during our Brazos and Beyond BBQ Tour last Saturday. The sandwich reminded us of a steroid version of another of our combo-meat favorites, Stanley's Brother-in-Law sandwich in Tyler. The Brother-in-Law combines sausage, chopped brisket and cheese on a bun. Loco's BBQ Po Boy may be the biggest sandwich I've ever seen. It combines chopped and sliced brisket with sausage on a massive hoagie bun, with your choice of onion rings or fries. The price is a cool…