>>4193876Good call. The GH6 is an excellent camera. Not exceptional in low-light, but it's no slough either.
I would strongly advice you to start with lighting the products properly, as oppose to simply getting a fast lens. The wider the aperture, the softer the image will be. This is especially true for cheap/kit lenses, like the one you have. You also get a shallower depth of field when shooting wide open, especially on longer lenses or if you shoot really close to the product. Clients typically want their products to be sharp and in focus, even when obscured by mist (perhaps more so when using mist). You may find that shooting at a slower shutter speed (1/400s for 100fps, 1/1200s for 300fps, etc) will yield better stills, but it may make the video look a bit choppy (standard is 1/200s for 100 fps, etc.). So experiment until you find what works best. If you do use a slower shutter, you will also need even more (and flicker-free) light.
But do try the kit lens before you buy another one. Since we don't know your specific setup, recommending a specific focal length can be a bit tricky. So, at the very least, use the kit lens to find the focal length that best suits your need. The Lumix G 30mm f2.8 (macro) could be a good choice. 30mm isn't particularly wide on MFT, so you will need a bit of extra space to work with. but it's also unlikely to distort the products. If you go below that, the product may end up looking a bit odd.