Well, I ended up using an older entrance I made that I'd saved as a blueprint and then built a small badger habitat at the entrance to my zoo. Weirdly they rarely leave their hard shelter and go into the main habitat, but that might be a design issue. I kind of just wanted to throw it down and see what the badgers looked like, so I think I'll bench them and scrap the habitat and start more seriously.
My plan is to build an "old meerkat habitat" that has been repurposed for prairie dogs at the entrance (first North American animal I will have ever used). To the west of the entrance I'm going to add in the "Sutherland Zoo Wildpark", which will contain the new European species, along with the moose, Arctic fox, and timber wolf. Then the quintessental big African section which will include the new meerkat habitat, as well as an ape house for the gorillas and chimpanzees (and an "old baboon habitat" that has been refitted for mandrills - until we get baboons).
Other odds and ends I want to include in this zoo are a "Cold Weather Cats" section (Siberian tigers, snow leopards, cougars), and a "Tropical Zone" (reptile house, cassowaries, lemurs, giant otters, etc.), and a red kangaroo walkthrough that leads on to an Australia house (koalas + exhibits). I also want to do an Aquatics Centre for the grey seal, sea lion, and both penguins, but I'm not comitting myself to that as yet because I haven't played in a while.