Wouldn’t Struthiomimus and Carnotaurus be a better replacement for Ornithomimus and the Terror Bird? Because Struthiomimus also lived with both Triceratops and T. rex in the late Cretaceous, and Carnotaurus was discovered not too far away from where Phorusrhacos used to live in Patagonia.
As for other dinosaurs featured in Prehistoric Park, there was a herd of Parasaurolophus and diplodocids (Apatosaurus/Diplodocus) from the show’s opening. They would make for great additions to your recreation of Prehistoric Park!