I used an A7C2 + Sony FE 50mm f2.8 macro. The lightbox was a custom build based on the design that I found linked on HN recently: https://jackw01.github.io/scanlight/. This was then mounted vertically on the toolhead of my 3D printer with the camera on a tripod, I then used the Z and X axes to scan across the negative.
Although I had success with PTGui and it "just worked", I didn't fancy paying for it and instead used Hugin in the end. This lead me to take around 63 pictures with 50% overlap.
The film was a 4x5 negative and after stitching I'd say the effective DPI was ~4500
