I use a sling bag (I'll try to take a Polaroid and post) with a main zippered pocket above a flap that covers the entire bag, including two zippered compartments and an open pocket. I put my three lenses in beer cozies with filters, shades and light meter in the main pocket. The body goes in the bigger of the two pockets under the flap and film and sundry in the smaller zippered pocket. The unzipperd pocket gets shelled film ready for loading.
In the bottom of the main pocket and the camera body pocket I secured with velcro foam padding from a lap top case. It may sound ad hoc, but it is very streamlined, comfortable, unobtrusive, and has greater padding than a reg. camera case. The sling bag takes advantage of the slimness of the body (mine is a Mamiya 6 about 3/4 to 1" slimmer than the 7) and is very comfortable (did I already mention that). This arrangement has been to Belarus, Romania, France, England, Wales and all over the USA.