Custom Design -- 2

Would need to be experienced in zbrush I have a bath and body business so I make bath bombs, I’m growing daily and am after some more detailed designs that I can have moulds made from to then use to make my products. I’d be after some celebrities and other characters, even some different objects. The celebrities and characters would just be the face of that celebrity. I would be after the file to then send to my 3D printer to get the negative printed that I can use to mould from. I was wondering if this would be something you’d be able to help with, it would be a frequent thing as there are lots of designs + characters I’m after. It needs to be smooth on the sides and have a flat back, as when naming bath bombs I need to take them out of the mould straight away and place them on a table to set, so the back must be flat. I can provide photos of a mould as reference as well as made up products, just let me know. :)