Preheat oven to 400 degrees. Add smoked paprika, salt, brown sugar, and pepper to a small dish then mix to combine and set aside. Place bacon in a large, cold cast iron or other oven safe skillet then turn heat to medium and cook until bacon is crisp. Remove to a paper towel-lined plate to drain then chop when cool. Remove all but 1 Tablespoon bacon grease from the skillet then turn heat up to medium-high. Squeeze lemon juice over salmon then sprinkle seasoning mix generously on top and rub in lightly. Add salmon to skillet skin side up then saute for 2 minutes. Flip then saute for 3 minutes, and then place the entire skillet into the preheated oven and bake for 6 minutes. Divide lettuce between two plates then top with chopped bacon, tomatoes, avocado, and BBQ salmon. Serve with your favorite salad dressing - I recommend Italian, balsamic vinaigrette, or Basil Vinaigrette.