Mjm, I own a tricked-out Classic basic plinth with a Classic 3 uni-pivot tone arm and base. When I first bought the Classic 1, I had a lot of difficulty matching a cartridge. No point in rehashing all of that now. If anyone is interested, they can pull my old threads.
It is worth mentioning, however, that IME two cartridge brands DO work well with the VPI JMW uni-pivot arm, namely the Sound-Smith VPI Zephyr and the Lyra Delos and Kleos. I used to own the Lyra Delos and give it top grades. I moved up to the Kleos, and I think it sounds even better.
I surmise that most of the other Sound-Smith cartridges will do just fine with the JMW uni-pivot. If one has any questions, they can call either Mike or Jack at VPI, or Peter Ledermann at Sound-Smith.
The Zephyr is my back-up carty when the Kleos goes in for service. Which raises an interesting point. I sent my Kleos to Andy Kim, the owner of the Needle Clinic, located in Washington State, for a check-up. Andy has garnered many compliments on A'gon.
I haven't gotten the Kleos back yet, it's in the mail. But all Andy had to do was clean and polish it. I was quite surprised because the stylus had at least 1500 hours of use on it. I pushed back and asked Andy how much life was left on the stylus and if he saw evidence of uneven wear. Andy reported at least 90 percent life left; no evidence of uneven wear.
To Kleos owners out there, or maybe Jonathan Carr, does this make sense?? If so, that says quite a lot for the Kleos, aside from its great sound.