Cut the fish into bite-sized pieces and season with salt and pepper.
In a medium bowl, mix the flour, paprika, garlic powder, and cayenne pepper. Add the club soda and whisk until smooth.
Heat oil in a skillet over medium heat. Dip each piece of fish into the batter and fry until golden and crispy, about 2–3 minutes per side.
For the slaw, combine the shredded cabbage, cilantro, and lime juice in a bowl. Toss and set aside.
In another bowl, mix sour cream with chipotle sauce until smooth and creamy.
Warm the tortillas on a skillet or directly over a flame for a bit of char.
Assemble tacos with fish, slaw, and a drizzle of chipotle crema. Serve with lime wedges.