I want to introduce you to the Canon 5D Mk II as a full-frame 35mm sensor workhorse camera. Not only do you have a very wide choice of Canon's excellent lenses to use on this camera but the wide aperture of the Canon EF lens mount allows you to mount many other older manual lenses from different lens mounts by using an adapter.
With a full frame 35mm sensor then you are comfortably in the field of publishable images. Even the original Canon 5D has a 12.8 megapixel sensor which is more than enough for publishing quality. I have this camera but I tend to use the 5D Mk II more often because it allows for higher ISO speeds without showing much grain in the image dark areas. But if you are put off by the price of the Mk II (or the later Mk III) then the original 5D should be more than enough for your needs and these can be picked up used very cheaply.
If you mount older lenses using an adapter then you should use an "AF confirm" adapter if you can get one. These give a bleep when an image is in good focus and is almost essential when you are using old manual lenses on an electronic camera. For manual lenses, focussing was almost always using a focusing screen with a split prism in the centre with micro prisms surrounding it and manual focusing was very easy with this. For the split prism in the centre then the two halves of the image would line up correctly and the speckliness for the micro prisms surrounding it would change to being plain and clear. But the focusing screens with modern electronic cameras do not have these focusing prisms (unless specially ordered) and so focusing old manual lenses is difficult and requires the electronic help that an "AF confirm" adapter can give you.
You will be surprised about how high a quality some of these old lenses had and can still demonstrate today mounted on an electronic camera. The manual lenses for the Olympus OM system, for example, were all of very high quality (except for the zooms) and most of them are capable of producing poster-sized images when mounted on electronic cameras. The lenses used on the Voigtländer Bessamatic were also of very high quality. Some of these old lenses give a pleasing look in the out-of-focus areas of their images. This is called having "good bokeh" (this is for "prime" "fixed focal length" lenses - zoom lenses both old and new mostly have very poor bokeh). Some high quality modern lenses, in their pursuit for ever higher contrast and resolution, can lack this "good bokeh" that some old manual lenses can give you. Even poor quality old lenses can give pleasing bokeh such as some Russian M42 mount lenses. Using the wide opening for the Canon lenses in this camera and combining it with old lenses with their AF confirm adapters can open up new areas of photography for you. If you have an interest in old 35mm manual lenses and you want to see the sort of images they can produce then the Canon 5D with the many AF confirm adapters available for different mounts is the perfect camera for you!
The pictures in this gallery will be limited to photographs of Canon 5D cameras themselves with lenses from other systems mounted on them. Photographs taken with lenses used on this camera will have their own gallery.