I'd buy a line level to synth level (Eurorack) converter. Then I'd buy a traditional hardware synth. MIDI does polyphony VERY well. CV does not. A Keystep Pro or Eurorack sequencer with a separate MIDI OUT would be my go to.

Once you're done mucking around with polyphonic sounds within Eurorack, you've spent a ton of money for functionality that's usually pretty weak. So, in my opinion, why try to get X to replicate Y badly when you can just patch in something that does Y already?