I vote for the Bronica GS1 6x7 ( its only around 1 kg) or if you are happy with a rangefinder the mamiya 7 with booth you get 10 pictures and with the Bronica you can shoot with a 4.5x6 , 6x6, or 6x7 back so you have all the choices!
Jerry Uelsmann works with the Bronica so it can't be bad!
Mine is 15 years old and I had not one single problem with it! Bronica is the most underrated camera in the world!