Hey there L0kEZ,
The full array of Hours of Darkness assets is not available just yet.
We pushed the first batch live with TU6 a couple of weeks ago, and we'll be adding more in the next couple of title updates.
TU7 is not too far off; while I'm not totally sure if NPCs will be included then, you will certainly have more assets to experiment with soon.
And I don't think this will change anything about your plans for zombie maps
/CJ