Intellijel Quad VCA is great. I’m happy with it.
For random voltage take a look at Mutable Instruments Marbles and Make Noise Wogglebug. Both are fantastic but different approaches to generating randomness. Wogglebug can do some Buchla Richter type random voltage or work like an additional oscillator or random noise generator. Marbles has the ability to do Turing machine randomness which is fun. I have and like them both.