Cut the pound of bacon into 1/4-inch strips and scrape into a stockpot over medium heat, stirring to separate bacon strips. Cook until bacon is crisp, then use a slotted spoon to move the bacon to a paper towel lined plate.
Drain all but about 1 tablespoon of the bacon drippings from the pan and return the pan to the heat, dropping the temperature to low. Add the onion and garlic (and crushed red pepper flakes, if using!) and cook, stirring frequently, for about 5 minutes, or until the onions are translucent and soft.
Pour in the chicken stock and tomatoes and half of the reserved bacon, then raise heat to medium high, bringing the mixture to a boil. When it is fully boiling, stir well, then add in the linguine noodles, using tongs to toss it until the noodles soften enough to be submerged. Add the lid, drop the heat to low again, cover tightly, and simmer for about 10-12 minutes, stirring frequently, or until the noodles are al dente (cooked mostly through with just some resistance in the center when bit.) Remove the pan from the heat.
Stir in the grated cheese and the cubed cream or neufchatel cheese, cover again and let stand for 5 minutes. When the 5 minutes are up, toss the noodles in the sauce until the cream cheese is melted and the sauce is thickened.
Serve the noodles garnished with the remaining bacon and the parsley and sun-dried tomatoes.