Exhaust Manifold Replacement

Hello my fellow 4Runner Gurus. I had a question, my exhaust manifold has a leak and wanted to replace it myself. Which manifold should I put on it?

My 4Runner is a 05 SR5 and has an exhaust manifold leak. Getting the P0171 (too Lean) and you can hear the ticking pretty loudly just not sure which manifold brand (OEM or Aftermarket) to get. Also not sure If i will have to replace the cats on it as well.