Thanks a lot for your comments, it's been super useful!
Based on the feedback I'll be getting the rackbrute 6U instead of the smaller 3U and I'll replace the shapeshifter with a couple of plaits, which are smaller and cheaper too. I still like the shapeshifter a lot though, and having some extra space in the case I might buy one at some point.
As for the filters, I'll go with the Polaris and the Optomix. The G-Storm's Tonus is really interesting and having the input mixers makes it a good candidate for a small system like this, I'll keep it in my 'cool modules' list jus tin case I want to add more filters in the future.
Xaoc's Zadar seems to be a reasonable replacement for the Quadra given the cost, features and size. The Quad VCA I was planing to get still seems a good choice so far.
Regarding the effects I like the Chronoblob 2 suggested by Lugia, but I think I'll get a Pico DSP instead of the Purrvrrb. The Pico DSP is smaller and can provide different effects. The Erbe-Verb sounds really great and I might buy one once I know a bit more about modular synths, for now the Chronoblob 2 and the Pico DSP will work just fine.
The top row is a bit more expensive than my original rack proposal, but it will be much more flexible and much more fun to play with.
The second row of the case are some modules I'm still considering:
- Most of the time I'm already using all the LFOs in the Minibrute, so I guess having the Batumi will be really useful.
- The 2S clock a bit limiting, as Lauprellim said, and I've been considering the 4ms clock dividers, but having the Pamela's New Workout would give many more options.
- A part from that I think I may be short on mixers, maybe I could add the MI Links or something similar if need to.
I'll be getting my first modules in the next few days . Anyway, I'm still open to suggestions if you guys think I got this rack all wrong or if there are some modules I should reconsider.