I think Show Chrome/BigBikeParts made a single top-clamp in chrome that was identical to the OE aluminum one. The OE aluminum one can be shined to a high polish, with a little work. I had a buddy that took his OE clamp to a gunsmith, and had it engraved (like firearms engraving), and polished.
Aeromach still makes chrome risers with individual clamps for Valk. They used to make a
Reaper single top-clamp that worked with their 4" honda risers. I have it on one bike.
A lot of guys glue Velcro to the OE top-clamp to hold cell phones and GPS, and all manner of electronic tomfoolery.
The Reaper.

If shopping around for a single clamp, remember that Hog and Kawasaki use a 3.5" riser spacing design, and everyone else (and Honda) uses a 100MM (4") spacing.