Maybe I'll take a look on small (BIG) modules which can supply VCA and ADSR functions. This will optimize your rack space.
Polaris is a very good filter with lots of modes, which is ok. I think that VCOs and Filters are something very personal and it depends on needs and what final user likes.
I'll go for Nano Modules ALT and Nano Modules QUART, respectively.
ALT has 4 clear VCAs in only 8 HP, so you're saving 4HP. Q
QUART are 4 AD-Looping envelopes, which can act as LFO too an, again, in only 8HP.
We have now 8HP remaining and, we can add Transient Modules 8s as a sequencer (little sequencer, but very funny and powerful).
You can find an sketch of how your rack should be with this changes. Just CLICK HERE and you can take a look on it.
I hope this helps you.
Rot