great idea - but try this no more than 5-6 modules - just the ones you will start with:
a sound source, a sound modifier, a modulation source, a way to play, a quad cascading vca - and something else that you think you want/need
and then once everyone has gone - huh - looks ok to me - buy it and play with it, at least until you have a good idea how everything works together - and don't worry about what modules to buy to fill your case - they will work themselves out over time - maybe after a month or 2 add another module or 2 and repeat
"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