I use UK standard layout, and Apple UK for work. It always takes me a few minutes to switch between them, but both are absolutely fine for programming. Just the odd placement of # that bothers me a little, but I tend to use that only for Python comments - which I tend to do more commonly from a keyboard shortcut anyway.

I believe the lower cable connects the two boards. The upper cable is for connecting to your device, so would only be connect to one of the boards when in use.