Sift together flour, cornmeal, baking powder, baking soda, salt, sugar into a bowl and blend in butter with your fingertips until mixture resembles coarse meal.
Stir together sour cream and water, then stir into flour mixture with a fork until just combined.
Drop dough in 4 evenly spaced mounds on a buttered baking sheet and bake in the middle of oven until pale and golden and cooked through - 15 to 20 minutes. Cool biscuits slightly on a rack.
Make Filling While Biscuits Bake:
Brown kielbasa in a large heavy skillet over moderate heat, turning it and transfer it to a bowl with a slotted spoon. Our off all but 1 tablespoons fat from skillet, then cook the tomatoes, onion and jalapeno, stirring, until tomatoes are softened, 1 to 2 minutes.
Toss tomato mixture with kielbasa and stir in cilantro, lime juice, and salt to taste.
Split warm biscuits and spoon filling and sour cream onto bottom halves. Put tops on biscuits.