Hi Rell,
Sadly no Tuskless and no ivory from Moz permitted into the USA.
I have hunted one of the main buff areas that Zambezi Delta hunts (with the concession holder).
BUT for trophy Buffalo, Sable and Eland I would personally prefer Niassa Reserve hunting areas during the months of late July, August, September and October (have hunted all of these).
The delta would be better during the hot late September, October and into November. This place would be good if you wanted a couple Buff and a Sable.
If I were in your shoes I would (and have) hunt a Tuskless in Zim and then move on to Niassa. That is if you can find extra time off.
If not, Niassa for Buff, Sable, Eland est, then another time for twin Tuskless with someone like Ian Gibson , Andy Hunter, Theiry Labutt or Allan Sheering in the Zambezi Valleys areas such as Sapi, Chewore or Dande areas.

Lugenda River in the hunters paradise of Niassa;