Thanks a lot for the useful comments guys, highly appreciated!
I was definitely not aware of the possible grounding and impedance problems that I could have gone into.

The sputnik and wmd inputs and outputs look really perfect, but I am afraid they also are a bit on the expensive side for starting off.
Given that I could easily use a conversion cable between the jacks especially in the output, do you think I could use something like the malekko 8nu8r as output attenuation module?

For the input I am thinking about it, since ears has envelope follower but no 1/4 jack in, while the doepfer a-119 has the opposite problem if I remember well