Toss the chicken with 1/2 cup salsa, the juice of 1 lime and 1 tablespoon vegetable oil in a large bowl; let marinate 10 minutes. Mix the remaining 1/2 cup salsa, the sour cream and 2 tablespoons cilantro in a small bowl; season with salt and pepper. Cover and refrigerate. Gently toss the hearts of palm, avocado, radishes, the remaining cilantro, 1 tablespoon vegetable oil and the juice of the remaining lime in a medium bowl; season with salt and pepper.
Heat the remaining 2 tablespoons vegetable oil in a large cast-iron skillet or grill pan over medium-high heat. Add the chicken along with the marinade and cook until slightly charred and cooked through, about 7 minutes per side. Transfer to a cutting board and chop; season with salt.
Warm the tortillas as the label directs. Using 2 stacked tortillas per taco, fill with the chicken, salsa-sour cream mixture and lettuce and/or red onion. Serve with the avocado salad and lime wedges.