Hello and welcome to MG,

Let's see if I can try to help and also save some time for the people who usually help everyone by pointing the obvious:

  • "Seq. switch because I've heard people say they're important" -> that's not a good reason to buy any module IMHO. Buy them because YOU UNDERSTAND or at least strongly suspect WHY they are important. Advice: pick up a copy of the free VCV rack and experiment, understand what VCA's and switches etc can do. Remind yourself that an amplification section in modular (a VCA) can serve many more purposes than the amplification section of most fixed architecture synths, most of modules can be "abused" in funny and/or musical ways. A similar remark comes to mind for Beads, I mean sure, Beads, amarite, but if I ask Beads or Mimeophon or Arbhar, do you still have a firm answer and justification ?
  • Doepfer + 2Hp VCA: looks like the space would be better occupied by a MI Veils 2020. If you don't understand why, I can only offer RTFM as advice :-)
  • 2HP modules are great but a bunch of them cobbled together can get hard to wiggle - those things are tiny, mate. You may want to consider the user experience aspect when designing your instrument.
  • Case size: Trying to rock 2 voices in a GENERATIVE setup with this space is ambitious to say the least. I can't remember what the exact titles were, but there are threads about this on this very forum. Basically, if you want to go generative, the 2HP TM will likely not be enough, and you have no ways to do logic, almost no modulation source. In the (approximated) words of a wiser member of this forum, the utility modules are the shine for the fancy nice looking modules, without it they remain dull for the most part. VCV will normally help you realize those shortcomings. Usually I see the TipTop Mantis case being recommended a lot but if you keep your build centered around only supporting the M32, you may not need a case as big as the Mantis. My advice is to at least PLAN your modular in a bigger space to get rid of that space limitation in your head, see what you need and then pick a case for the use you will have - and leave some space for (limited, if you want) expansion, modular is almost guaranteed to open a lot of doors in your head, so it can be good to be ready for when that happens.
    Including M32: NO. If you are thinking about putting the M32 in anything other than its own casing, don't, unless you have a large case that has a lot of empty space, it's a waste of space and therefore money (because you pay for the space in the case).
  • Obligatory delay, reverb: why obligatory ? Unless you have very specific needs in terms of effects, like say the need for being able to CV control FX parameters, there may be other cheaper ways to handle this... As you have not included an Output module, I'm assuming you will feed this to a mixer or sound card of some sort. The latter implies a DAW, and therefore cheap great sounding FX VST's which could liberate precious space.
  • Doepfer mixer: if you intend to keep the build as small as possible, I don't understand this choice of mixer, there are smaller offerings, or similar sizes that offer more.

For your future research, plenty of excellent advice for similar questions. Type "generative" or "ambient" in the search bar from forum index and you'll have a lot to read.

Hope this of some use !

--- Voltage control all the things ---