Pat shrimp dry with paper towels and season with chili powder and pepper. Heat 1 tablespoon oil in 12-inch nonstick skillet over medium-high heat until just smoking. Add shrimp and cook until curled and pink on both sides, about 2 minutes. Transfer to bowl and cover with aluminum foil.

Add remaining 1 tablespoon oil to Skillet and heat until just smoking. Add chorizo and cook until lightly browned, about three minutes. Transfer chorizo to Bowl with shrimp.

Add onion and Thyme to fat left in skillet and cook over medium heat until onion is softened, about 5 minutes. Start in garlic and cook until fragrant, about 30 seconds. Stir in rice and cook until grains are sizzling and lightly toasted, about 1 minute.

Stir in clam juice, tomatoes, and saffron, scraping up any browned bits. Bring to boil, then cover, reduce Heat to low, in cook until rice is tender and liquid is absorbed, about 15 minutes.

Off heat, stir in cooked shrimp and chorizo. Arrange clams over top and sprinkle with peas. Cover and cook over medium Heat until shellfish have opened, about 7 minutes. Discard any clams that have not opened.

Remove skillet from Heat and let stand, covered, for 5 minutes. Sprinkle with parsley. Serve with lemon wedges.