Combine mangoes, peaches, poblano peppers, red onion, juice of 1/2 a lime, and 1/2 the cilantro in a large bowl to make mango salsa. Cover with plastic wrap and refrigerate, at least 1 hour, preferably overnight.
Mix sour cream, mayonnaise, ketchup, cayenne pepper, salt, and black pepper in a small bowl to make special sauce.
Preheat oven to 350 degrees F (175 degrees C). Arrange tortillas on a baking sheet.
Preheat a grill pan over medium-high heat; coat with cooking spray. Cook salmon until easily flaked with a fork, about 4 minutes per side. Transfer to a plate and flake into smaller pieces with a fork.
Heat tortillas in the preheated oven until warmed through, about 5 minutes.
Divide salmon among tortillas. Top with mango salsa, special sauce, shredded cabbage, avocados, and remaining cilantro. Wrap up tacos and serve lime wedges alongside.