I searched some cameras available in the market but it is hard to find a good middle format pinhole camera that is not wide, or at least not too wide angle. I also have being trying to find a 6x9 format camera in order to get as big negative from middle format as possible for contact print.
After sleeping on it for many weeks and asking for suggestion in photography communities, I realized I could install a pinhole in my Agfa box camera, it is not too wide and it is 6x9 middle format. I got a 0.4mm pin and installed in my old Agfa camera last night. Tomorrow I will do some self-portraits test.
If it works as I expect I am ready to follow my next project on making pinhole photographic portraits.