>>4294127>>429411712mp, maybe. Anything over 16mpx is an overkill. Film is kinda shitty, unless you like looking at individual grain shapes. If you need more detail just get a 2:1 macro and stitch. Pixel shift will get you no visible results.
>>4294093Mirrorless 16mp+ with macro is great - more than good enough and fast. For 35mm only you can get a Plustek 7/8xxx series. On a total budget I paid 40USD for a PacificImage 3650U which while slow, gave me slightly better results than X-T20 with 7a macro in some cases.
If going with a digital camera, for scanning sensor size doesn't matter, you scan at base ISO anyway. Use what you have. Flatbeds are generally garbage, but least finnicky.
