Fidelity Research FR-64x.....(with silver wire )
Do you mean FR-64s ? But the "s" is not necessary silver wire, it can be copper wire. When the wire is silver there is a sticker on the art "silver wire inside" or something like that.
I bought FR-64fx toneam (the black one) with heavy counterweight W-205. We will see how it works with my FR-7f cartridge. I'm gonna try my FR PMC-3 cartridge as well, but maybe i will need a lighter counterweight which i don't have (looking for one).
I'm not a fan of the silver wire, in my opinion copper wire is always better.