I did learn in my research that Trekking bars are HUGE - as in very wide. This may not be an issue for you, but as I have a quite short reach and have narrow shoulders this led us to go for riser bars instead. I would have loved them, but there you go. They do not appear to come in a range of sizes either.

The Soma Sparrows were of interest, but they wouldn't work for me either as they require a single shifting/brake "pod", so to speak, and those are not available for cantilever brakes. Otherwise there is limited space for hands...