In a large skillet, saute shrimp and onion in oil until shrimp turn pink. Stir in tomatoes and cajun seasoning. Set aside. In a large saucepan, saute garlic in butter for 1 minute. Stir in flour intil blended. Gradually add milk. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Remove from heat; stir in cheddar cheese until smooth. Add sausage; set aside.
Spread 1/3 cup shrimp mixture over each noodle. Carefully roll up; seam side down in a greased 13 x 9 inch baking dish. Top with cheese sauce. Sprinkle with pepper jack cheese and paprika.
Cover and bake at 350 degrees for 15 minutes. Uncover and bake 10 to 15 minutes more or until bubbly.