Among Canon EOS mount lenses in the focal length range you mentioned, the best choices would be the 135 TSE, 90 TSE, 50 TSE and the 85mm 1.4L IS. Also Sigma makes a 105mm F1.4 that covers the GFX sensor quite well, so that would be an excellent choice and you wouldn't even need tilt to get razor thin DOF. These lenses will all cover the GFX sensor, with the 85 just barely being usable wide open. You don't need the Arca lens mount for EOS lenses, or the view camera either, for that matter, as long as you stick with the tilt shift lenses. You can use a dumb adaptor and buy a $50 EOS film body to set the aperture. Of course, you would be well advised to go ahead and get an electronic AF adapter to eliminate the extra step in setting the aperture and also picking up AF, which is a huge bonus.
You would likely need a view camera if you want to use the 85 1.4 or 105 1.4 with tilt. As far as I know, there are no EOS to GFX adapters with tilt functionality. I have an M Line 2 and it works fine with the 85 and 105 lenses (once again, the 85 is marginal wide open). Best solution would be an AF adapter and the Sigma 105mm. I believe Sigma also makes a 135mm F1.8, but I have not tried that lens. The 105 works really well on the GFX, so I quit looking after I found it. Razor thin DOF is only so useful and it's very tough to nail the focus, even in a studio environment.