Hello guys! Im planning to build my first modular. I've read and watched a bunch of videos on how to start all this, but still it seems very confusing at this point, so it might be errors in here, maybe i miss some basic things. So feel free to comment and advice, i will appreciate it!
Few words about what do I wanna use it for.
Basically playing synths is my favorite time spending (what a surprise), but my job makes me move to a new place almost every half a year. At home I've got pretty solid MIDI-chained setup with Moog Voyager, Tetra, Analog4, a guitar that i sample into Octatrack, tb-303, bunch of effect processors and a DSI Tempest as drum machine. Obviously its not possible to carry all those with me. So i decided to sell the setup, get a small MIDI-sequencer with drum samples (considering Digitakt as a main option) and build a modular synth that is flexible and not huge.
Most of the time I play techno, but slowly reducing amount of percussion and moving to ambient-style soundscapes.
So my goal in this case is not to produce too much crazy blips and farts, but more stable musical sounds.
Thanks in advance:)

since the rampage has no attenuators like the maths, it very much likes living near an Happy Nerding 3xMIA or 4MS SISM or Triatt or something. Pams New Workout packs a lot of envelopes and lfo's into a small package, maybe have a look at it.

when planning for an digitakt (which is a nice idea btw.) you could maybe get a little light on those samplers? and maybe use the space of that tiptop one and pico drums and pico seq for something else?
(with your yarns you can utilize 1 or 2 or 4 midi tracks of the digitakt in your rig over midi, no need for more sequencers imho)

maybe you can fit an disting mk4 into there? very useful multi purpose module for small systems.

also: VCA's (yes you can really never have enogh of them)
Zlob VnIcursal VCA, befaco hexmix vca, intellijel dual/quad vca, tangle quartet, veils etc.

Thanks for your advice man!
First of all I've chosen a case, it will be Mantis from Tiptop, its very light, has power, has travel bag so i can fly with it as a hand luggage. 208hp is pretty much space.
I've added a Zlob VCA, so minimum amount is reached:)
Also made a decision not to go for Rampage, seems too complicated and frustrating at the moment.
Tiptop One will stay in case i'm gonna use some extra audio source to be processed through the synth.
I've added 909 bass drum with the Pico sequencer cause I found solid kick to be important (thats why i love Tempest). Later I will assemble all analog drum-rack and it will move there.
Disting is a cool little thing! Ill just go for it because of this. Also added Pam's Workout, from your recommendation.
Got one more filter from Bastl and changed 4 to 6 inputs mixer.
Added 2 hp freez to use with external input.
I use noize pretty often so here is Doepfer's noize generator.
The last thing is Morphagen. Very flexible and sounds just awesome.
Now i think its too many effects... What else do I miss?

if i were you i would think about the feature overlap between clouds and morphagene and if i really need two similar tools in my first two rows.
if one of the two is enough for you at first, you could use the space to get maybe some attenuverters, switches and some logic to spice up your patch possibilities.

i am too inexperienced with all those different forms of noise and all the modules that offer a noise output to give you really good tipps here ;)