/diy/ - Do It Yourself

This is kind of a silly question, but is there a good way to stack large amounts of PCBs?

I'm working on a modular design which should be able to accept an arbitrary number of modules, but I can't seem to find a good connector for it.
The obvious answer is the ubiquitous stackable headers, but I can't find a datasheet on what their rated resistance and current handling is.
I'm probably looking at ~20 PCBs stacked, with each PCB drawing around 50ma on +/-9v rails.

Pic related is similar to how my design is set up.