As the title states, I'm trying to find out what make/model medium format cameras also accept 35mm film. I know Holgas can be modified to shoot 35, but that's not what I'm looking for. I know in the past, a friend had a 120 camera that he was able to shoot 35mm in no problem; unfortunately we've lost touch so I can't ask him what it was. Any help would be greatly appreciated.
There is a 35mm kit for the Mamiya 7 as well, and possibly the 6 too.
There are also people who run 35mm through RBs and RZs with homemade adapters.
If you work the monetary numbers a bit, however, you see that you are just as well off cropping down a 120 or 220 frame than using a 35mm adapter in a medium format camera...except you are even better off practically, because you are not limited to the width of 35mm film (i.e. you get more compositional options; and perhaps an even more exciting way to look at it is that you get what amounts to a good deal of view-camera-esque vertical shift either way of the horizontal center line of the medium format film frame, which also gives you a good deal of control over the shapes of things in your composition).
Now, if you really want to shoot pretty extreme panoramic format very often, at exactly the same height and width every time, and there is an emulsion that you want to use that is available in 35mm that is not available in medium format, I would say to have at it without feeling too silly.
If composing with a panoramic frame in camera helps you, you can simply make viewfinder masks. The great thing about shooting onto film that covers the entire film gate is that you can make a set of masks for your ground glass, each with a different aspect ratio.
The elegant solution of the person who owned my Mamiya C33 before me, who wished to visualize the cropping required to fit the square pix onto a vertical piece of 8x10 paper? Use a fine-tipped Sharpie and a ruler to draw lines on the ground glass. It doesn't get in my way, and I actually use the lines from time to time.