Makes sense. Then would you recommend trying to zinc plate everything else (not the gates)? I know the two pieces in picture one sitting next to the stack, the one piece slides into the other so powder coating would not be an option as I would assume they would never fit.
Correct Nick, parts that slide into each other are good candidates for zinc plating. The bottle gates I have powder-coated white for durability over paint, the vend stack/rack is also a good powder-coat candidate. I would match the shelves and bottle stack/rack in the same color. The gate assemblies, arms that connect to the bottle gate and the rear linkage, can be powder-coated but may require a little work to get functioning smoothly; we zinc plate, yellow zinc, these arms.
To sum things up, you'll need to determine what items require movement or have close tolerances; these parts may be best suited for zinc plating, the others can be powder-coated.
Hopefully helpful...