Ahhh, OK...hm, what I'd do would be to drop the Pam's right off the bat, because you don't really need timing and/or more modulation with that Maths in there. Instead, you need a proper input module and something isolating for an output because, if you're using external inputs, you have a higher possibility of AC leakage and other sorts of crud coming in on the outputs.
So...drop the Pam's. Then, you need to get a Nonlinearcircuits Envelope Follower (which also contains an input preamp and a 1/4" input jack) and a Happy Nerding Isolator. This leaves 2 hp (like it has now), and for that, my suggestion would be York Modular's Lockhart Wavefolder, which would also give you some selective distortion capabilities.
The envelope follower will output a modulation CV based on the input amplitude, which you'd find useful with either the Rings or the Wavefolder. And the output module features transformer isolation, which means you've got some "iron" in the signal path which would play nicely with a bit of overdrive to it, adding some nice euphonic warmup to the outputted signal.