Make sure( or Shure, LOL) that the cartridge has a reasonably high compliance as the 111 is lower mass than is common today. It was from an age of very high compliance cartridges, they are much less common today. I would stick to MM as they will work better in the arm. The new Ortofon range looks good but why not try the V155? It is the type of cartridge the arm was designed for and should sound better in it than in the MMT. The arm board should be available from SOTA, if not try a local custom wood shop or a place that works with acrylic. I think Vinyl Engine has tables showing arm and cartridge compatibility.
Good cartridge to use with SME IIIS
I'm working this question through the back door--hope I'm not wasting bandwidth... I've got an early Sota Saphire which currently still has the MMT tonearm. I've also got a mint SME IIIS tonearm that I'd like to try out--any suggestions on what would be a good cartridge match (under $400) that would make it sound better than the MMT (with a Shure V15typeV)? Also where do I get the necessary mounting board?