Have you looked into using a Camerz long roll camera? Camerz has two versions, one with 46 mm films and the other with 70 mm. I tried the 70 mm one once and it produced excellent images. It will give the negative of the size of 645. But you can shoot hundreds of shots on every 100 ft roll. There are a few places to process long roll films. Just search the internet. I still have a few partially used rolls in the freezer now. I had to cut the film at a few foot each to process in my own darkroom. I did that only for testing the camera. It worked really well. I am planing to adapt a 645 film magazine on it in order to shoot 120 or 220 films with the camera. It can be done but takes time. Camerz long roll cameras are dirt cheap now. Can be had from eBay for less than $100 shipping included. The 75 - 150 zoom lens on it is an amazing piece of optic. The Camerz camera with the adaption of a 645 magazine will make an excellent studio portraiture camera.