Wheels for Roadster: 16 or 17″ suppliers?

Servus. I currently have the 16″ Spikeline rims and 20mm discs around on my roadster. I might be looking for something more extravagant. Which manufacturers are there (because 3-hole rims)? Bzw: Where can I find hole circle adapters from 3 to 4, or 5 holes?? Unfortunately, I only get old offers displayed via Google.