Pre heat broiler.
Heat the olive oil in a large skillet over medium heat. Add the onions, paprika, cayenne and salt and pepper to the pan, stir and toast for about 3 minutes. Add the garlic to the pan, stir and let cook for a minute being careful not to burn it then add the tomato paste.
Add the pancetta, chopped clams, and smoked clams to the pan, stir and cook for 3-5 minutes. Add the dry fideos to the pan, stirring until toasted. About 3 minutes. Add the shrimp and stir again.
Meanwhile, in a small sauce pan, combine the chicken broth and reserved clam juice and bring to a simmer. Carefully pour the chicken broth and clam juice mixture into the pan, stir and let it simmer for 5 minutes or so.
Place the pan in the oven under the broiler until golden and crispy on top. Make sure to watch, you don't want broiler burn!
Garnish with parsley and serve with lemon wedges.