Adding a female even if you find one is very risky. I speak from experience. Male/female select each other; I'm not sure if the male has the final word or they both agree democratically, but the fish have to bond of their own accord however they work it out. So unless you can place the male in with sveral females and see if he bonds with one, I wouldn't risk it. He will live fine on his own. Observations in the habitat suggest this species lives in isolation except when they spawn. My present male is nearing the end of his seventh year now, pretty good for a fish with a normal four year lifespan, and he has been on his own except for one brief period of a couple months.
I did introduce a female, after he had been in the tank for maybe two years. She was close to the same size, so I thought I might luck out; I was not fully aware of the bonding aspect then. They acted a bit odd with respect to their interaction, but still spawned four times, then the male decided that was it and I found her dead one morning. And this was in a five-foot tank, well planted; still not sufficient space for her to escape. I didn't read the signs obviously, but their back and forth interactions and spawnings led me into complacency.
I don't know how large this tank is, nor how many fish of the species named, so difficult to suggest other fish. Avoid cichlids, period. The male Bolivian Ram will undoubtedly now consider the tank "his," and any cichlid will be deemed an intruder. It amuses me to see my Bolivian ruling the tank when the mood strikes him, which is almost always at feeding time when other fish annoy him. He had the entire group of Bleeding Hearts corralled in the upper half of the tank for several minutes once.
Byron.
