Definitely a new cartridge, it’s much better to have several cartridges to understand what do you like in your system. If you’re looking for a brand new cart then forget the MC if you’re not willing to spend $1500+ on it and remember that Denon 103 has conical tip (the cheapest profile ever) and your tonearm is not designed for such a low compliance cartridge!
I would advice to check Garrott P77i or higher models from this respected Australian manufacturer, those models comes with advanced profiles (Micro Scanner II and Frits Gyger). However, the prices are not cheap (in Australian Dollars) and on the vintage market you can find better solution, especially if you will look for Audio-Technica AT20SLa, AT-ML170 or 180, Victor X-1 or X-1II or Stanton 881 or 981 (those rare models are superior compared to very expensive MC carts) and the stylus profile is Shibata / Micro Line / Stereohedron. Amazing MM cdartridges in my opinion, and still 3 times cheaper than any good MC. These cartridges will put your 2M Black in the dust.
I would advice to check Garrott P77i or higher models from this respected Australian manufacturer, those models comes with advanced profiles (Micro Scanner II and Frits Gyger). However, the prices are not cheap (in Australian Dollars) and on the vintage market you can find better solution, especially if you will look for Audio-Technica AT20SLa, AT-ML170 or 180, Victor X-1 or X-1II or Stanton 881 or 981 (those rare models are superior compared to very expensive MC carts) and the stylus profile is Shibata / Micro Line / Stereohedron. Amazing MM cdartridges in my opinion, and still 3 times cheaper than any good MC. These cartridges will put your 2M Black in the dust.