Combine chili powder, garlic powder and salt and pepper in a small bowl. Pour the lime juice over the tilapia and coat with the chili powder rub. Set aside to marinate while you make the peach salsa.
To make peach salsa, combine all the salsa ingredients in a small bowl. Taste and adjust lime, salt and pepper to taste.
Heat a skillet over medium heat, and add a dash of olive oil. Cook the tilapia for 3-5 minutes, turning occasionally until fish is cooked through. The fish should be white throughout, rather than opaque.
While the fish is cooking, heat your tortillas. Heat a large cast iron pan over medium to high heat, and cook each tortilla one at a time for 2-4 minutes on each side, until they are lightly charcoaled. To assemble, take a tortilla, add the fish, then top with the peach salsa.