Bagman saddlebag supports are apparently quite hard to find, but a call to Wallingford Bikes turned one up. I ordered one without the quick release (because Ti versions weren't in stock), but the one that showed up turned out to have the quick release feature instead (which weighs a bit more).
The support snaps onto the saddle rails with an allen screw, and installation takes no more than 3 minutes, even if you loc-tite the assembly. However, the Bagman has a fatal flaw, which is that the struts supporting the bag proper are mere rods that slip into a hole in the saddle attachment, which is then held entirely with friction by a couple of small screws (about 3mm in diameter) and a bolt.
Whoever designed the Bagman has never done a major bike tour involving rough roads or rough stuff, because even though I applied loc-tite to all of these screws, after about 15 days of rough riding (or 3 months of daily commuting on my Munich Commute) and the rods would slip out. The first time this happened it was in heavy Munich traffic, which was quite disconcerting. Fortunately, the design is such that you won't lose the small screws if that happens.
Since then, I've tightened the screws periodically, and just before any long tour. Even so, during this past tour, my bagman came loose in this fashion not once, but twice. The proper solution is to undo all the screws, mark the rods, and then put in divots in the rods to prevent this sort of motion in the future. But seriously, it's poor engineering to expect the customer to put in fixes for obviously bad design.
I cannot therefore recommend the Bagman for serious cycle tourists who are not mechanically savvy and willing to perform the modification. This is a pity, since I still think saddlebags are a better solution than panniers for light touring, but given my need for CPAP therapy, perhaps my days of light touring are past. The search for a better solution continues...