Almost a year later and the modular bug has returned. I've figured I can fit a Mantis on my desk, which allows for double the space I was initially counting on. I also followed Lugia's advice and played around with VCV Rack and can't wait to get on with the real deal. Please bear in mind that although I primarily make synth pop, I would also like to dabble with other more experimental genres inspired by Hiro Kone or Caterina Barbieri. This modular will mostly serve the purpose of creating textures and layering samples with synthesis, since I have most of the rhythmic and melodic areas and effects covered between my Analog Rytm, Digitone, and an Erica Synths DB-01 and H9 that I picked up since I last posted.

Here's the rack I would like to end up with:
ModularGrid Rack

I guess the main doubt is whether the Cloud Terrarium is too big a module for a build this size. I do like the sound of it a lot but I'm open to alternatives. I'm also very excited by the 258t coming out. Let me know anything you would change here, but no larger cases please.

And, since I can't splash out £4000 at once, here is what I think I could get started with:

ModularGrid Rack

Thanks again for all the help and advice.

Edit: See below for updated rack