I would recommend Plogue's OPS7, they have put considerable amounts of time and ...

I would recommend Plogue's OPS7, they have put considerable amounts of time and effort into reverse engineering the original chips. The interface is a little clunky but it sounds fantastic. https://www.plogue.com/products/chipsynth-ops7.html

Edit: a YouTube video about the reverse engineering process from David at Plogue: https://www.youtube.com/watch?v=XJ97iXQrqzw