Rough part about an exhibit pack is deciding what comes in, as the mechanic has been neglected, with the addon that there's a lot of cool and interesting critters that could be added.
Personally, the ideal pack for me would be:
King cobra (Headliner)
Tuatara
Pig nosed turtle
Torny devil
Central bearded dragon
Frilled lizard
Burmese python
Black mamba
Patherson chameleon
Common agama
Madagascar day gecko
Mata-mata
Basilisk
Surinam horned frog
Chinese crocodile lizard
Overally with a big focus on Oceania and squamata, but able to fulfill multiple needs.