Follow the package directions for making the cornbread with the eggs and milk. Let cool and break into large chunks.
In a large, deep skillet, melt 6 tablespoons butter over medium-high heat. Add the onion and celery and cook until softened, about 10 minutes. Stir in the half-and-half, parsley, sage, thyme and basil and bring to a simmer. Add the oysters with their liquid and cook for 2 to 3 minutes. Season with salt and pepper to taste. Add the cornbread chunks and gently toss to coat.
Spoon the stuffing into 2 buttered 3-quart casserole dishes, dot with the remaining 2 tablespoons butter and bake, uncovered, for 40 minutes.