They were kept just in four European zoos, jayjds2. Two German, one Italian and in London. Maybe the population gone because they were not self-sustainable. I don't know. Ok maybe the low altitude may had influence, because they are high-altitude animals. I don't know about their history in USA, do you know?
They never did super well in the USA. The last even suspected animal (nobody was quite sure) died in 2002. Now, back to the rest:
West African Giraffes, I would agree with, but only under special conditions. The AZA zoos would have to let their "reticulated" giraffes die out. At this point they are so screwed up that they don't look like any giraffe (sub)species.
That being said, Masai giraffes are doing just fine

.
20 Malayan tapirs- there is no room for them in the zoos. Not many zoos want to work in tapir habitats- they are big among South American animals, take up lots of space, and their population is already pretty good.
10 Malayan tigers- if sourced from other zoos, those would benefit the population greatly.
30 indochinese tigers- if you ask the director of the zoo and tier park in Berlin, he will tell you that you've already seen one. However, to manage four tiger (sub)species in captivity would be a bit much (but get rid of the Bengal and white tigers, it'd make the process easier).
20 great blue turacos- I have no idea what this bird's population and genetic diversity is looking like. I know it's been rough in the past, but I think we have got their husbandry down (or close to it) at this point. A small population of say five or so wouldn't be bad.
20 Central American bushmasters- I honestly don't know which species of bushmaster we have right now (or even both).
20 golden lance heads- wouldn't be the worst idea.
Now, after all that, what I would import:
A pair of king of saxony bird of paradise- not anywhere in captivity, and I really like them.
2.3 Papuan mountain pigeons- very small captive population of them.
Small, varied populations of many (mostly) common frogs and toads, mostly ones that zoos aren't working on. Chytrid fungus is going to threaten all of them. Eventually, I would work my way to:
2.2 Goliath frog and the plant they need- work out husbandry (hence the small population) and breeding, then import more in very small numbers to hopefully save the species. Perhaps work with zoos.
Small numbers or various South American birds. I mean things that are not represented in zoos, like blue winged mountain tanager, but would do well. Also probably some manakins because I like those. Maybe 1.1 Wilson's bop as well. Most of my imports would be small numbers of tropical birds, frogs, and toads.