There have been questions regarding piston sizing for these systems. Not that it matters more than a customer's experience on the street and on the track, here they are:
Front: 38.1mm / 31.8mm / 27.0mm (for both 368mm and 378mm kits)
Rear: 31.8mm / 31.8mm
There are many, many manufacturers making pads for these calipers. In fact, I'm not aware of any major ones who aren't.
And there is currently no feature to include the pad wear sensor. Often, these will start to melt under higher temperatures and malfunction anyway. If the latest ones can handle more, it should probably be looked into for the future.