Update: I have completely redesigned this and posted as a new project https://www.thingiverse.com/thing:2829855
As requested here are the files for the dual Z setup I recently set up. One of my main design goals was to not use any set screws. Here are the specific parts I used.
Note: I used the factory Dual Z setup as a base, therefore a right side lead screw bracket wasn't needed.
T8 600mm 3D Printer Stainless Steel Lead Screw Coupling Shaft Mounting Bearing
BIQU GT2 Synchronous Wheel 60 Teeth 8mm Bore Aluminum Timing Pulley for 3D Printer 6mm Width Belt (Pack of 2pcs)
BIQU GT2 20Teeth 3mm Bore Aluminum Timing Belt Idler Pulley for 3D Printer 6mm Width Timing Belt (Pack of 5pcs)
Uxcell a16031400ux0530 3D PRINTER 2GT-6 Ring Closure Timing Belt Closed 852mm Circumference, HSS