Anything will do. I have the MS folding keyboard for use on the go and have a USB wireless mouse and keyboard at home with the dock. Both work just fine!
I'm using basic stuff
Display output to an old LG TV using a msft wireless Display Adaptor
Then a run of-the-mill USB mouse, plug into 950XL using a OTG adapter.
Guess I'm saving up for a hub...
Just tried a very cheap adaptation. I dusted off my old USB-hub (with card reader), and plug in the regular (read old) mouse and keyboard, and a pen-drive... and it works