The new SmallRig camera cage for Nikon Z8 is finally in stock at Amazon US:
Also in stock at AmazonCA | AmazonUK | AmazonDE | AmazonIT | AmazonES.
SmallRig is also sold at B&H Photo.
For international shipping, check the official SmallRig online store.
Additional information is available here:
Just announced: SmallRig accessory ecosystem for the new Nikon Z8 camera