Welcome to the forums! Just a quick note, Chameleons are actually not native to South America, but I'd like them anyways, and I like your suggestions!
At this point in the game, South America is in the most need of additional species out of all of the continents...granted that's my opinion, but it's a fairly shared one, so it may actually be an over all "community supported" fact/non-fact.
My list of South American mammal wants, priority wants in bold, Even though overall what I think South America needs most are more primates, species-wise none of them are actually that high up on my list. Just more of a general-generic priority. 6 at minimum, I'll put a * by the ones I'd personally choose.
Spectacled Bear
Patagonian Mara
Coatimundi
Brazilian Porcupine
Tayra
Two Toed Sloth (as exhibit, sadly)
Black Howler Monkey*
Squirrel Monkey (probably Common but any species will do)*
Collard Peccary
Pacarana
Golden Lion Tamarin*
Ocelot
Red Howler Monkey*
Emperor Tamarin*
Spider Monkey (any species)* - more popular to most people, I would rather get a Squirrel Monkey over a Spider Monkey, if given the choice. But I do still want them in the game.
Bush Dog
Common Marmoset
Cotton Topped Tamarin
Cuban Hutia
Alpaca
Tamandua
White Headed Marmoset
Pygmy Marmoset
Brown Spider Monkey
Brown Howler Monkey
If we talk about birds, most would be exhibit birds except noted with (H)
Toco Toucan
Hyacinth Macaw
Scarlet Macaw
Scarlet Ibis (H)
Keel Billed Toucan
Roseate Spoonbill (H)
Blue and Yellow Macaw
Military Green Macaw
Blue Headed Macaw
Spix's Macaw
(and more Macaws as you really cannot have too many IMO. I'd throw money at a 20 pack of Macaws TBH.)