Absolutely, but they might be hard to find. What region of S. America and what kind of habitat do you intend to simulate?
Some relatively common Amazonian offerings:
Some species of Palaemonetes, in the same genus as North American ghost shrimp (e.g. P. carteri); small, claw-bearing shrimp Euryrhynchus spp. (primarily exported from Peru); various species of Macrobrachium (e.g. M. amazonicum, M. sp. "Otorongo"); large filter-feeding shrimp (A. gabonensis, mostly exported from W. Africa but present in the Americas as well, and A. scabra if you're willing to be loose about your definition of S. America)...
Euryrhynchus are often shy and liable to be eaten by larger fish, whereas the Macrobrachium might turn the tables ... a lot depends on the tankmates you plan to include.