BassistBiker, I have been studying the Salsa website lately, searching for the best gravel touring bike, for a couple weeks.
The Journeyman frame, according to some Q/A page, is exactly the same for the 700c and 650b versions. My advice is based on your height. Close to 5 ft 6 inches, get the 650b. Closer to 6ft, get the 29er. Get a second wheel set later for the other size.