Two things spring to mind.
One, why do you want/need a 4 post slipper? So you can lock it up when using a remote starter................. you have a starter motor
The other is that while the WSB bikes use plain ramps, the factory use 6 ramps, they also take more looking after. The ball and ramp design will go all year with little attention. The plain ramps need servicing and lubing to keep them in tip top nick. If you leave it you'll wear the ramps.
I'd get a Bucci or similar ball and ramp unit...........