Second hand modules was the way to go for me .
I just stuck to “factory built” modules from larger manufacturers ie doepfer ect.
Only been bitten once in 32 modules with worn sockets and it wasn’t a hard fix .
Move the Power supply switch to the side or on the back of the case and free up that space .I put mine on the side no problems at all.
Nothing wrong with obsolete modules can be found cheaply.
I build my case out of just second hand modules.