Hey guys, thanks for the replies,
I'll consider getting the 6U rack, I think it's the sensible choice just in case I need more space in the future. Regarding the modules sizes, I guess the shapeshifter and the erbe-verb are the guilty ones, can you suggest smaller replacements for them?

I've watched a couple of videos about the Expert Sleepers Disting suggested by Laupellim, it seems a very powerful module, however, at this point I'm not sure I would know how to use it or how to patch it with the 2s, there's a lot I still need to learn. Right now I lean towards something that can produce smooth and soft sounds, as the 2s can already pretty harsh.