Heat the oil in a large sauce pan. Season the shrimp, softshells and oysters with salt and cayenne. In a shallow pan, combine 1/2 cup of masa and flour. Season the flours with salt and cayenne. Dredge the shrimp in the seasoned flour, coating the shrimp completely. Dredge the softshell and oysters in the seasoned flour, coating completely. Fry the seafood in the hot oil until golden brown, stirring constantly, about 4 minutes. Remove from the oil and drain on a paper lined plate. Season with salt and hot sauce. Split the French bread loaves in half. Spread the mayonnaise on both sides of the bread. Build the sandwich with the fried seafood, lettuce, and tomatoes. Serve with Zap Potato Chips.