If you look at things like the Lightbath videos, something is sequencing the voices... in his Loom series, for example, it's Mutable's "Marbles" module.
If you are only processing external audio, I'd suggest replacing Plaits with something like Batumi or Pam's New Workout (and you'd have a little room left for another modulation source in 2-4 hp). That way, you could bring a signal in through Ears, process it with Rings and Rainmaker, and use Batumi/Pam's/extra little module to modulate various parameters.
If, on the other hand, you expect this system to generate all of your sound, you're going to be disappointed. As Lugia said, you need modulation sources... this system has none (in those same Lightbath videos, he uses Mutable's "Stages" module for this role... and in his other videos, he uses many other things).
One other thing I'd suggest... go for 104 HP instead of 84. The size difference is small, and the cost difference will be negligible, but it will give you more flexibility.