I need help with some equipment advice, I'm basically a hobbyist on a limited budget. I currently have a Pixel 7 Pro and an Olympus OM-D E-M5 Mark II camera with stock (14-42mm EZ) and macro (M.Zuiko Digital ED 30mm F3.5 Macro) lenses. Neither of these systems can really do what I need.

I need to be able to take slow motion video (120 fps or better), ideally at 4k resolution, of close-up shots of products and plants with dry ice mist effects swirling around. I've attached an image to give an idea of the kinds of shots, although they will be generally closer up and obviously with motion.

For the camera I'm thinking of getting a Lumix GH6 (although advice is welcome on this point) and after that I'm not sure what kind of lens would be best. Since it's slow motion light will be an issue so I'm thinking something larger, and also even though these are macro-style shots we don't want to have to get too close and risk creating shadows (larger lens = bigger shadows). I'm planning on shooting this from the hand although I do have a tripod mount (some shots may use it). In a perfect world this lens would also be good for still photography (again, product photography, mostly close up images) although I do have my current macro lens.

Does anyone have any advice of a lens that fits this situation and doesn't break the bank? Looking for maximum value if possible.