Combine first 7 ingredients in a medium bowl; stir gently.
Place bread in a food processor; process until coarse crumbs measure 1/2 cup. Combine breadcrumbs and butter in a small bowl.
Arrange oysters on a broiler pan. Spoon about 1 tablespoon crab mixture over each oyster; sprinkle each with about 1 teaspoon breadcrumb mixture. Broil 7 minutes or until tops are browned and oysters are done. Serve with lemon wedges and garnish with chives, if desired.