Numbers, I don't know and probably won't until it opens. I honestly don't think anyone knows. I can give some rough estimates from what I've read.
Confirmed are 5 lions and 3 Cheetahs.
Up to 6 or 7 elephants
12-14 Giraffes
30-40 Impala
About a dozen each of Zebra (probably Grant's) and Ostrich
Maybe some smaller birds like Guinea Fowl, but I don't know anything has been decided on yet.
Both Warthogs and Red River Hogs will be there, probably just the pair of each that is currently in the collection.
All of the land is space that was unused for exhibits. Only a few offices and education trailers were on the site prior to construction. Look for the powerpoint presentation the Zooplantman posted back in April for all the detail you could want on placement and design.
Where the Elephants and Giraffes are now will be home to Camels (don't know which species) and a Black Rhino. Haven't had lions in nearly two years, but Cat Row where the lion used to be I think is becoming a Texas Predator exhibit. At least that's the last thing I saw in the media. As per my position as the zoo, I should make it clear that I will only post information that is widely available to the public.