Make the bacon marmalade: Cook the bacon in a large nonstick skillet over medium-high heat until almost crisp, 5 minutes. Pour out half of the drippings, add the onion to the skillet and cook, stirring, until the onion browns, 10 more minutes (add a splash of water if the onion sticks). Stir in the hot sauce, sugar, vinegar, and salt and pepper to taste.
Form the pork into four 4-inch-wide patties; season with salt and pepper. Heat the olive oil in a large skillet over medium-high heat, then add the patties and cook 4 to 5 minutes per side, topping each with a slice of cheese about 3 minutes before they're done.
Spread the bacon marmalade on the bun bottoms and top each with some lettuce, a patty, a tomato slice and a bun top.
Drizzle the remaining lettuce and the chopped tomato with olive oil and vinegar, and season with salt and pepper; toss. Serve with the burgers.