Heat oven to 200°F. Cut each fish fillet lengthwise into 4 strips. In shallow glass dish, mix 7 tablespoons of the lime juice and garlic. Add fish; turn to coat. Let stand while preparing biscuits.
On work surface, mix flour and cornmeal. Separate dough into 8 biscuits. Press both sides of each biscuit into flour mixture, then press or roll into 6- to 7-inch round.
In 12-inch nonstick skillet, heat 1 1/2 tablespoons of the oil over medium heat. Add 2 biscuit rounds; cook about 1 minute on each side or until golden brown and cooked through. Place on cookie sheet; keep warm in oven. Cook remaining rounds, adding 1 1/2 tablespoons oil to skillet for each batch. Wipe skillet clean.
Heat same skillet over medium-high heat. Add fish and lime juice mixture, chiles, salt and pepper; cook about 5 minutes, turning fish once, until fish flakes easily with fork.
In small bowl, mix salsa, sour cream and remaining 1 tablespoon lime juice.
Using slotted spoon, remove fish and divide evenly among biscuit rounds. Top each with cabbage and 1 to 2 tablespoons salsa mixture. Fold biscuit rounds in half over filling. Serve with any remaining salsa mixture. Garnish with lime wedges, if desired.