Get the 6u case not the 3u:
- you will need it sooner or later and it will save you money compared to buying the small one now and then selling that and buying the bigger one later
- the minibrute and the 6u fold together to fit in the bag so better for transporting
spend some time studying utility modules - what they do and how to use them
they may seem comparatively boring, but they are the lifeblood of modular synthesis. They allow all your other modules to breathe and are relatively cheap
mi links and kinks are a good starting point - you get a buffered mult (for multing pitch cv), 2 small utility mixers, a basic waveshaper, some logic (a comparator), a noise source and s&h in 8 hp
add something like a sequential switch and a quad vca (veils is great - especially if you want to bring some external sound sources up to modular levels) and you have a great starting set of utilities
I always get at least one utility module for every “functional” module
seriously consider a disting mk4 - in a small case it adds tons of functionality - in a larger case it’s a “if only I had another xxx module” lifesaver
personally I’d recommend getting the case, links and kinks, disting, veils and 1 to 3 of the modules you mentioned - maths, rings and morphagene would be my picks (in order of priority) - if you can find a used clouds at a reasonable price then get that instead of morphagene perhaps
that’ll give you 2-4 sound sources (minibrute, rinds, disting, maths) , enough modulation (maths, disting, minibrute), enough basic utilities (maths, links, kinks, veils) and something to effect them with (clouds or morphagene)
output from either veils or the effect straight to an outboard mixer/audio interface and monitor from there - get a couple of 3.5->6.5mm mono patch cables for this