and what goes in racks?? ah yes, modules - what you already have WILL influence recommendations!
it's entirely possible that you have at least one, or more, module that couold be temporarily sidelined in order to fit something bigger in... but unless you share your rack we won't know...
my recommendation would be for a matrix mixer, preferably doepfer, for ergonomics reasons... and some stack cables...
another possibility might be a sequential switch...
but as far as I know you already have these...
do yourself a favour - make your rack public and copy and paste the url into the thread!!!
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities