Nikon introduced a Z-GR1 extension grip/plate and Z-VP1 bracket for the Z FX cameras (adds Arca-Swiss compatible plates):
Unfortunately, the Nikon bracket is only available in Japan at the moment. So you're left looking for a different bracket in the rest of the world.
The following other brackets and plates are available:
Fugasun L plate
Gabale QR Arca-style L-plate for camera
Honglai HL-Z6/Z7L Arca-style L-plate for camera; also features hand grip extension plus an extra cold shoe option.
- PZ-178 Arca-style camera plate
- BL-Z Arca-style L-plate for camera
- PZ-130 Arca-style plate for FTZ adapter
- BL-FTZV2 Arca-style L-bracket for the FTZ adapter
LIM NK-Z71BK Leather half-case with Arca plate
Markins:
- PN-Z7 Arca-style camera plate
- LN-Z7 Arca-style add-on L side plate for PN-Z7
Meike MK-Z7G Slim Arca-style plate with grip extension — This grip/plate seems to have been redesigned a bit over time. It features an extension of the hand grip coupled with a full Arca-Style plate for the remainder of the camera bottom. The battery is accessed by moving the battery door from the camera to the bottom of the added grip
- PLMNBN11 Intelligent L bracket (for Z II's with MB-N11 grip)
- PLMNBMN72 L bracket for Z II's
- PLNZ672 L bracket for Z II's
- BZ7 Arca-style base plate
- BZ7-L Arca-style L-plate for camera
Smallrig
- APL2258 Arca-style L-plate (optional cable clamps) (What I'm using)
- APL2244 Camera cage
- 4523 Arca-style L-plate for Nikon Z6 III
STC Fogrip Unique folding grip extension with Arca-style L plate across camera bottom
Sunwayfoto PNL-Z6 Arca-style L-plate
Three Legged Thing Zelda Arca-style L-plate (available in copper or grey
The Arca-style foot Thom uses for his FTZ adapter is the Stabil FTZF.