The FR64S sounds phenomenal with Koetsu stones; any one who’s had that combo will tell you the same. The FR64fx is also quite good if you’re on a budget. Silver vs. copper versions on these arms doesn’t matter too much; don’t stress over it. The stock 64fx base is quite good but a B-60 or Ikeda VTA-06 base is recommended for the 64S. The stock FR headshells are all pretty bad. The Koetsu deserves better. I'm partial to the Ikeda headshells (20g, very thick aluminum). Also a Graham Phantom is quite serviceable for Koetsu stones (but not as good sounding as the FRs) if that’s what you’ve got on hand.
I tried a Jade once on a Clearaudio Universal 12" and it was an awful match lol. I don't know how much of that was compliance/mass matching versus the carbon fiber arm tube material, but the Koetsu sounded like it wasn't happy. That same arm sounds GREAT with a Shelter Harmony (carbon fiber body), so there is definitely something to the arm/cart matching thing.
The Ikeda seem like they’d be a great match too, and share lineage with the FR arms, but they will cost you a good bit more than a used FR64 series arm.
I tried a Jade once on a Clearaudio Universal 12" and it was an awful match lol. I don't know how much of that was compliance/mass matching versus the carbon fiber arm tube material, but the Koetsu sounded like it wasn't happy. That same arm sounds GREAT with a Shelter Harmony (carbon fiber body), so there is definitely something to the arm/cart matching thing.
The Ikeda seem like they’d be a great match too, and share lineage with the FR arms, but they will cost you a good bit more than a used FR64 series arm.