Whooo...this is not bad at all! Your prospective choices are pretty spot-on, actually. As for the reverb on your chord parts, though...I'd be more inclined to do that outside of the modular via an FX send/return on your primary mixer to have better control/blend over that signal. Otherwise, you run a risk of getting the modular's output signal a bit too muddy and cluttered. However, what I would suggest is to process the chord parts in the modular with a phase shifter to get a nice, potentially spatialized sense of timbral motion. As for the filtering on that, you might consider some sort of resonator...maybe aim for that classic Korg PS-series sort of multiband depth. Both of those together would be really wild...very much in that classic Basic Channel sort of sonic zone, given the dubby/spacy sweeping you'd get.
Another VCF to consider might be DINsync's SARA VCF...it's also a state-variable, but it has a very odd architecture that the manufacturer refers to as 'dual opposed-core', which should be in that dual-peak style of the Praga but might actually be stranger in character. Plus it has two big purple knobs...which would look very visually intriguing for live gigging.
Arrangement definitely needs work, tho...hang on a few minutes...ok, maybe a bit longer since MG's acting up, but...
Howzzat?
Went ahead and, as suggested, fleshed it on out. You'll note a few modules missing from the original, notably the Tallinn and Peaks, which were replaced with the Optomix and a bit of the RADAR. That last thing is a killer...eight looping AD/ASR generators with a separate controller module, the BLIP. I'd say that satisfies all envelope generation needs for this build! I located it centrally to make it convenient to the entire build at the same time.
Batumi (and Poti) added, along with the Belgrad (too little space for the SARA VCF, but the Belgrad fit just fine), along with a Delptronics LDB-2 for analog 606/808-ish drums, then a six-in stereo Ladik mixer, with the Morphagene in 'post' position followed by the Erica Output. Sequencer/clocking area was reordered to straighten out the step-down flow of the clock from the Metropolis thru to the Erica Seq and sequential switch (now in position to switch clock outputs from the Euclidean). All voicing to the top row, where the MTE 4 is set to work as a unity-gain muting mixer for a channel of the Veils. Also, the DSP is post-Optomix to make it convenient for tinkering with the output(s) from that. Didn't cram in a phaser, but there should be enough in there for extreme sonic damage purposes.
Think that'll work?