Here's my R32 hubs before I hacked the tab off.
The tab acts as a spacer, and without it, the anchor will be positioned wrong and nothing will fit right. Some Zs don't have tabbed hubs and instead the anchor is slightly thicker to accommodate. When I tear down my car for the frame up, I'll pull the anchors and replace them with the thicker Z units (depending if I can find them of course).
We had a discussion on this topic a long time ago in the vert forum of all places. I went and looked it up 'cause I remember someone teaching me about the difference between the two anchors as I thought they all had the annoying tab.
Get whatever e-brake assembly you can. If you don't want to hack the hub tabs off, Nissan might still have the anchors available. I would suggest getting them off an N/A Z.
Hopefully that clears up some confusion for you.