Heat oil in heavy large skillet over medium heat. Add scallops and shrimp and saute until just cooked through, about 3 minutes. Using slotted spoon, transfer seafood to bowl. Add garlic to same skillet; saute 1 minute. Add tomatoes and half of basil; simmer until sauce thickens, about 10 minutes. Increase heat to medium-high. Add clam juice and cream and simmer until thickened to sauce consistency, about 6 minutes. Add penne, seafood, remaining basil and toss. Season with salt and pepper.