I’ve got the chromatic modules and what I’ll say is that they’re pretty decent except that I don’t much care for the Eudemonia filter. It doesn’t have much character in my opinion. In my setup now I’m much more enjoying the sounds of 2 hysterias through a ring mod and low pass gate. To my ears that setup sounds much better and more interesting than the same two VCOs into the Eudemonia with the Ataxia modulating the filter cutoff and vca. For the same price you could get a Typhon which sounds fabulous and does a lot more. In short, I would look into alternatives for the filter/vca.

For your second setup, plaits is a very robust module and it is going to give you a very different experience than a pretty basic analog vco. You can approximate that setup in vcv rack so I would try it there.

If it’s not required to be racked, I would consider the beat step pro. Affordable, two melodic sequencers (pitch, gate, and velocity) plus 8 drum triggers. Patterns up to 64 steps and a couple of different options for pattern chaining, muting, etc. Hard to beat for the price.

The chromatic modules are a good place to start, as you can get a VCO, VCA, Filter, Mixer, EG, and LFO all in just three modules for around $100 a piece. It’s what I did and don’t regret it. Definitely go for a 6U case. My rackbrute 3U filled up very fast and now I’m kind of stuck debating with myself if I want to get the 6U and have 9U which is more than I need, or switch to a different 6U case and sell my 3U or keep it as a separate case for a small system later. Either way it’s a problem I wish I didn’t have.