Q.: Are any modern dual-pivot brakes made for step-through bikes (i.e., with the cable stop on the bottom arm and the clamp on the top)?

I've put Tektro R-559s on my commuter and really like them; I'd like to do the same for my wife's, but they don't seem to make them for step-throughs. It's not possible to switch the clamp and the stop, as far as I can tell.

All the recent factory set-ups I'm seeing out there (e.g. this, this, this) have diamond-frame-style brakes with the cable going up the seat tube and then curving around 180 degrees, which looks totally inefficient.