Another strong thumbs up for the Wienmann/Dia-Compes. They are really excellent brakes despite their association with suicide levers. The calipers themselves are just great.
Two suggestions...
1) If you are running tires fatter than a true 1 1/4, consider using both QR cable hangers AND levers with QR mechanisms built in. This allows the calipers to open up for a 1 3/8 tire or even a knobbie. I can't picture how to do this on a mixte for the rear brake, but if you need to car rack the bike and need to take the FW on and off a lot, having the double QR system on the front makes life easier.
2) Consider using the Koolstop MTB pads. They allow you to adjust for rim width and toe-in. The latter is a really big deal as it's the difference between silent stopping and raise-the-dead squeeling. They also have a longer braking surface than the older Mathauser pads (or the KoolStop Continental knock offs).