I had the same problem with gold German rams. I bought two at the same time I bought my Bolivian rams. One gold one died within a week, the other a week later. The symptoms were exactly as you described--hiding near the bottom and rapid breathing. I felt completely helpless, and it was heartbreaking. They're beautiful fish.
I tried diagnosing their problems and medicating them to no avail. I tried praziquantel for internal parasites and various antibiotics. Nothing helped.
I wish I could help you but all my reading suggested that they're heavily dosed with steroids and antibiotics to keep them healthy while being shipped (usually from Asia) and they're generally just not that healthy by the time you get them. Mine appeared perfectly fine, too, especially the second one that died. Fine one minute and an hour later, panting like crazy.
My only suggestion would be to try finding them from a breeder in the states so you know they're not shipped overseas. I've seen some on Aquabid. I've decided to stick with the Bolivian rams. I personally think they're just as beautiful and mine are thriving.