I do have soft hands, however, I am leasing my horse out to a 4H rider and her hands still move when she trots/canters. She will be taking lessons but I just want my horse to be as happy and comftorable as possible.
You could find a curb bit with short shanks that has a french link type of mouthpiece in it. That might be the best bet. If you can't find one like that by a bit with the shanks you want and a bit with a mouth that you want made of the same metal and take it to a metal fabrication or welding shop and have them put it together for you. If you use stainless steel it should shine up well enough that you won't be able to tell the difference.