I can only tell you about the plants I've had luck with , I don't think any of them come from south america .
Java fern grows very well . I either tie or rubberband it [not tight] to rocks , driftwood ,or other deco . It will take hold on it's own over time , you can simply let it float in the water . low light tolerant , they don't get planted in the sustrate .
Anubias grow pretty much the same way as Javafern , only more slowly . They also should not be planted in the subtrate . Alae sometimes grows on the leaves .
Java moss , just put it in the tank , no planting . It can easily grow out of control , even trap fish , I've had this happen twice , they got trapped and couldn't get out they sufficated , It is good for raising fry however .
Criptocoyne , not sure what type have [ some leaves are reddish brown and some are green they came in one pot and have gown nicely ], I only know it's been alive for at least six years , and for the last three I have done nothing special to keep it alive .That goes for the other plants . no I'm wrong , every other water change I add seachems iron and carbon supplements .[ half the recommended doses
these plants in my opinion would be just fine for your ram , though I may pass on the java moss , I'm sure there are many other suitable plants for your tank , these are pretty easy to care for .