I think you will prefer the 8580. If I remember correctly, the prophet64 bunch actually specify that an 8580 should be used. I also think the bassline samples they provide, are made with 2 8580 chips, using a dual chip adapter board which they also designed. You may be able to get such a board from them, but they don't provide the extra chip.
It seems you have come a long way from scoffing at electronica, huh? :-D Good stuff. I look forward to seeing the music you produce. Oh, also, you may like to know that music production, and home studio establishment can be very addictive.