With no hesitation I would go for bmpcc with canon speedbooster. I recently shot this film https://vimeo.com/116101747 just with this camera and I was amazed with the DR versatility, sharpness and many other stuff. Just get a few extra batteries or a solar powered charger like goal zero or something. Camera is super compact and I don't see any reason to shoot 4k. And it also has a timelapse mode so you have some beautiful 1080 DNG files to process.