I ended up ordering a Tubus Vega:
...from Wayne at
The Touring Store instead of the more heavy duty models. The new-to-the-USA Vega is basically a Logo without the additional side racks.
This is for my commuter and I won't be doing heavy loaded touring on it, so the 25kg capacity of the Vega should be enough. Wayne also has some adapters that move the rack back a little for additional heel clearance, so I ordered a set of those too.
I should have it later this week.