I wasn't happy (like many people) with the z-stop mount that comes with the printer. i felt it was flimsy, easily out of alignment, and hard to accurately adjust. I played around with an inductive sensor, but had reliability issues, which is really bad for a z-stop.. So i decided to simplify.
After searching around, i couldn't find what I wanted, so I did what any sensible person does: roll my own :).
The three sets of parts are a z-stop mount for the z-endstop, a bracket to which a screw and some nuts are attached for adjustment, and a cap to make for a bigger target (optional, but I use it). Left and right versions are included (and marked with an "L" or "R").
For each side, you just need 2x M5 bolts and t-nuts for the top bracket, an M3 x 50mm or so bolt for the adjustable screw, one M3 nyloc, and one regular M3 nut. This will work with a stock hotend, and, if using a suitable longer adjustment screw, also with hotends that protrude further into the build area.
Update 3/18/2017: I switched my printer to a dual-z stop setup, so I also made a left-side version and included it here.
Use pliers to squeeze a nyloc in the top hex recess, flip it over, thread a regular M3 nut on the longer adjustment screw of your choosing, and while applying pressure, screw the bolt through the bracket into the nylock. This will ensure everything is properly seated without any play.
Screw the cap on the bolt, try to make it square to the bolt.
Use longer M3 screws to mount the lower holder to the movable build plate, right where the FRU8LUU linear bearing is. My FT-5 had several leftover bolts that were suitable length.
After mounting the bottom bracket, screw the z-stop switch to the bracket using two m3 bolts and two nylock screws, add two M5 screws and nylocks (again, there were leftovers in my kit), position the switch "arm" over the cap on the adjustment screw, and fix in place.