Anyway, after a ton of VAF research, Orndorff video watching, and builder website reading, I settled on the "other" method, which puts the hinges on the long face, and really only bends with the short side of the 2x4 (or 2x8 cut in half). You really only want that much bending the skin anyway, because the bend needs to occur locally at the radius, not away from the trailing edge. If the wood is imparting force in the middle of the skin, you will end up with the dreaded "bulge."
Here's my bending brake being assembled. I had six hinges, so why use them. I grabbed these 2x4, which were nice and straight, and just long enough for the trailing edge. I'll need to replace these for the flaps and ailerons. I read somewhere they need to be more like 5 feet long for those.
Here it is after assembly. On the left, you can see my skin, that needs to be bent. In the middle, the three dowel rods I purchased. While I was standing in the store, 1/8" seemed too small, so I bought a few different sizes at $0.50 each. Of course, everyone was right on, 1/8" is perfect.