Never heard of a custom replacement. You don't really need it. Consider it as a nostalgic artifact of the period. It was intended to reduce the jostling when riding over potholes and rough roads. When it's cranked down enough to dampen the rough road feedback, it actually becomes dangerous when returning to the relaxed ride of the smooth road. So, you have to make sure it's loosened up for normal riding. Lotta folks thought it was for stopping high speed wobble, but it really wasn't intended for that. Upgraded steering and suspension components are the proper solution for that.
Friend of mine had the steering damper on his (other make) bike, and he believed in having it always cranked down. You never wanted to ride alongside him, he'd weave and wander across the entire lane...