These are my four biome packs, with a stand four plus one, with an additional three species if an animal pack is desired:
Open Spaces
1. Przewalski's horse
2. Emu
3. European rabbit
4. Southern ground hornbill
Exhibit. Common collared lizard
The horse would probably be the main flagship species for the pack and is an ideal representative for the Asian steppes. The emu is a much-wanted bird that lives in the deserts and grasslands of Australia, while the Southern ground hornbill adds another bird that lives on the African savannah and is suitable for mixed-species enclosures with large herbivores. The rabbit may seem an odd choice, but they are an endangered grassland animal from Europe that is very recognisable and could add another one of those 'petting zoo' species.
The collared lizard is chosen as the exhibit species because it represents the grasslands and deserts of North America, is brightly coloured and is, when accounting for size, one of the fastest animals on Earth.
5. Maned wolf
6. Patas monkey
7. Bar headed goose
In the case of an animal pack, the maned wolf is the obvious choice for representing South American grasslands and could be mixed with the giant anteater. The patas monkey is my choice for a plains primate, being the monkey best-adapted for running on open ground and also, unlike the baboons, being small and docile enough to mix with a broader range of African savannah species. And I added the goose as a second steppe species, simply because I like them so much.
Rainforest
1. Red river hog
2. Goodfellow's tree kangaroo
3. Siamang
4. Ocellated turkey
Exhibit. Meller's chameleon
For this pack, the siamang would probably be the flagship, representing the jungles of Southeast Asia. While Central Africa has many potential species, the red river hog is probably most sought-after and the tree kangaroo is the top choice for the rainforests of New Guinea. Finally, the Central American rainforest is represented by the stunningly beautiful ocellated turkey, which should hopefully be able to be mixed with the Baird's tapir.
A chameleon is an obvious choice as an exhibit species - while I was tempted to include a Madagascan species, I have recently come to see and really like the Meller's chameleon, which inhabits montane rainforests in southeast Africa. I have seen them in real-like before and they are huge, one of the largest chameleon species, which is a bonus in my mind.
5. South American coati
6. Golden bellied mangabey
7. Crested wood partridge
As for an animal pack, the coati is a commonly-kept and recognisable animal which would also be the pack's only carnivore. The mangabey is not kept that much, but I have seen some brilliant footage of them playing with the gorillas they are mixed with at Burgers Zoo in the Netherlands and I just want to be able to recreate that. And the partridge is a small, attractive, ground-based bird that would help fill small spaces and tropical houses with colour and sound.
Mountains
1. Gelada
2. Golden takin
3. Yellow throated marten
4. Common wombat
Exhibit. Olimpia's ground beetle
The gelada is one of my most favoured primates - I would much prefer seeing these included than the baboons, not least because they are docile enough to mix with a range of smaller animals that a true baboon would just eat. The takin could be the flagship species, as they are strikingly coloured and an ideal representative of the mountains also inhabited by the giant panda. The wombat is not an obvious mountain species, but I have seen photographs and film of them flourishing in the snowfields of the Australian Alps and are to my mind the best Oceanian species for this pack. And the marten is there because I love it so much and they inhabit montane forests throughout Asia.
As the exhibit species, I have chosen the threatened and brightly-coloured ground beetle that is endemic to the Piedmont mountains of Italy - they have been subject to a successful captive breeding programme in the past as well, so we know they can be kept in zoos.
5. Klipspringer
6. Spectacled bear
7. Himalayan monal
The klipspringer is a good species to represent mountains in the savannahs and temperate grasslands of sub-Saharan Africa, although the rock hyrax would probably work equally as well. The spectacled bear is the obvious choice for representing the Andes Mountains and the Himalayan monal adds a huge splash of colour to this pack, which mostly contains quite dull-coloured animals. I tried to think of a North American species, but not only could I not think of one I particularly wanted, but there's nothing here I would sacrifice either.
Islands
1. Tasmanian devil
2. Victoria crowned pigeon
3. Fossa
4. North Island brown kiwi
Exhibit. Lord Howe Island stick insect
For the island ecosystems, I think that the Tasmanian devil would probably be the flagship species. The kiwi is the obvious New Zealand representative and, while I would love the sifaka or another lemur species, I think that Madagascar does need a species that isn't a primate - the fossa fits that niche well. New Guinea is one of the most biodiverse islands and I think it does need at least one more species - with the tree kangaroo in my Rainforest Pack, I think the crowned pigeon is the best second choice.
The stick insect seems like the most obvious exhibit species for such a pack, considering that it has been datamined before, but there are plenty of other options that would be just as good such as the Fiji banded iguana, Solomon Island skink, mountain chicken frog, Mallorcan midwife toad and panther chameleon.
5. American flamingo
6. Sri Lanka leopard
7. Vancouver Island marmot
If Islands received an Animal Pack, I think these are the three best animals. The American flamingo is the customary reskin, which would represent both the Caribbean Islands and the Galapagos. The leopard might seem an odd choice, but they are the top predator of Sri Lanka and leopards are a well-requested species. Finally, the marmot is similar to the prairie dog but is a bigger, more strikingly-coloured animal that is being saved from extinction by breeding in zoos and represents a northern temperate/taiga island environment otherwise unrepresented in the pack.
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Asia still has only 2). I'm in desperate Need for more Plants 
) and Watering Systems that simulate Rain from Time to Time
