I believe they are called red head tapajo. They get fairly large. What size tank do you have them in?
I had one of these awhile ago. They are beautiful fish. If u have sand as your substrate, u can see them sifting through it.
They definitely do well in groups. As u probably know the elephant nose gets fairly large, u can leave one, two will be pushing it, three definitely not unless u will b getting a larger tank soon.
If you want cichlids look into rams or some other small cichlids you could then add a few schools of different fish like rainbows and tetras
Kribensis also would work.