Movie film for projection usually has quite a high density range, and 8mm is going to be tough to contrast mask unless you have very precise registration equipment, so I'd try making an interneg, probably in 35mm or medium format. You might have to experiment to find a good film, but I'd start with Ektar 100 and Portra 160NC, presuming the original is color. TMX or FP4+ for B&W.
There are a few copy methods, and much depends on the quality of the lens with something that small. I'd recommend something like a Canon FD 20mm or 35mm Macrophoto, similar Zeiss Luminar, Leitz Photar, or Olympus micro lens. These are lenses that use RMS thread and have an adapter to attach them to a bellows on the camera. Canon had a movie film copy stage that was designed for use with the FD 20mm Macrophoto to copy Super 8 to 35mm, but one doesn't see for sale it very often.
You will also need to filter the light source to match the film for color, and this could take some experimentation, but with an interneg, you've got a little wiggle room to filter when you print as long as the neg is pretty close.