Bring a large saucepan of salted water to a boil. Add the macaroni and cook until still slightly al dente, about 10 minutes.
Drain and set aside to keep warm.Whisk the eggs in a large bowl until frothy.
Combine the Velveeta, butter, and two cups of the half-and-half in a large bowl.
Add the warm macaroni, tossing until the cheese has melted and the mixture is smooth. Add the remaining half-and-half, three cups of the sharp yellow cheddar cheese, the remaining grated cheeses, and salt and pepper, tossing until completely combined.
Pour the mixture into a 9 x 13-inch casserole or baking dish and bake for about 30 minutes.
Sprinkle with the remaining one cup of sharp yellow cheddar cheese and bake until golden brown on top, about 30 minutes more.