I've installed them in commercial kitchens in the past but not in a domestic setting. Can dig out the commercial firms if you want but they are unlikely to be interested in a domestic job.
I’ve used these guys. They’re good, and you can design & price it using their online tool. MR MDF core and they normally glue glav steel onto the underside to stop any warp so no clang, but heavy AF.
Not sure if the best place to ask, but has anyone here gone for stainless steel worktops in the kitchen, if so who did you work with?