None of them have the rice starch added like Enfamil A.R. You might try regular Enfamil and add your own cereal in. Maybe you could talk to your doctor and see what they recommend.
I agree with Kathleen, you could try just adding some cereal to a regular formula. Even better, you might try weaning from the Enfamil AR to a regular formula. We were able to stop thickening my dd’s bottles at about 9 months. She continued to spit for another month or two after that but we never had to thicken again.