Cook lobsters in 2 large pots of boiling salted water until shells are pink and lobsters are just cooked through, about 11 minutes. Meanwhile, melt butter in small saucepan. Add lemon juice and herbs. Season with salt and pepper. Serve lobsters with lemon wedges and warm herb butter.
Melt butter in a large saucepan or Dutch oven over medium-low heat; whisk in flour until smooth. Cook, whisking constantly, 2 minutes. Gradually whisk in milk, and cook, whisking constantly, 5 minutes or until thickened. Remove from heat. Stir in salt, black and red pepper, 1 cup shredded cheese, and cooked pasta. Spoon pasta mixture into a lightly greased 2-qt. baking dish; top with remaining 1 cup cheese.