What are u trying to achieve with an other voice?
How are u going to play the voice? What kind of modulation u intend to use?
Squeezing another voice in 28 hp is a challenge imho.
Maybe something like oxi coral if u are willing to use midi.
Wouldn't u be better of getting some more modulation, fiters, saturation, folders and/or effects?
I'd start with that to complement the M32.
Later u could add a new voice and put the M32 back in its own skiff.

-- Chrissozz

I'm more interested in "stand alone" type voice modules than building out a voice across several modules. The Oxi Coral looks interesting, especially since I am sequencing the rack w/ midi (NDLR). I have a couple LFOs in the rack, plus those the NDLR can send via the midi->CV converter in the niftycase, so I'm not desperate for modulation sources.

I'm also considering grabbing an intellijel shifty to do some note hocketing between the two voices (splitting a single melody line), and perhaps a 2hp Euclid to send gate patterns to the shifty...