The thing is, and this applies across the board to emulating the sound of one machine with another, is that for many extreme sound enthusiast, it is those little subtle characteristics, the quirks, the least effeble in words or maths aspects of the sound that we find so appealing and attractive. Those details are not likely to be replicated using anything but the original kit, and if one has fallen for that particular vibe, then only getting the original is going to satisfy.
On the other hand, there are others who don't care so much about 'just that one exactly' but want to make something equally interesting, or similar, reminiscent, but with it's own character, then it doesn't really matter if it's a spot on reproduction, just that you can create a similar effect.
If you're trying to get 'X or Y' sound, I'd suggest you live with getting close with software and a controller. Frankly, it's a bit desperate to want to remake somebody else's sound from 25 years ago, so do something similar your own way with whatever tools are most easily available today, wavestion VST and + controller, or vectron.
If you're willing to spend the money on a poly evolver or prophet VS to get that kind of sound -- well the VS is the exact thing you're thinking of, while the poly evolver will do something similar and a lot more. Do you have an irrational desire to own a cool piece of history (that's ok) the get the VS. Do you want an awesome modern poly synth. Get a PEK. Do you want to just get some inexpensive tools to achieve a reasonable version of the sound in your head -- vectron or wavestation + joystick controller and some time programming.