I would do a reptile house scenery pack.
-Argentine black and white tegu - an habitat lizard thats not a monitor for once
-A smaller tortoise like red footed or radiated - a nice contrast to our big boys
-West african crocodile - africa kinda lacks a croc and this one is a nice medium size
-Green anaconda (E)
-Tokay gecko (E)
-Panther cameleon (E)
-Japanes giant salamander (E)
I changed the formular here because a fourth habitat spot would be just another tort, croc or big lizard which felt kinda repetative so i transformed 1 habitat spot into 3 exhibit spots ( idk how many exhibit animals equal a habitat one so maybe add or cut how many are appropriate). Maybe you could update the iguanas so we could kinda have another habitat one.
Would come with:
-More exhibit customizeability like a null option, more sizes and shapes including a bigger one to house the anaconda and giant salamader
-Educational and museum like props like skeletons and displays
-A wallset that kinda fits the reptile house vibe but is generic enough to work for other things
-A expansion on the keeper talk to work with habitat animals like the new tegu and tortoise in additon to some small critters from the base game like lemurs