In all my NUCs computer I'm using Logitech Wireless Keyboard + Mouse. This keyboard and mouse connects to the NUC trough Logitech USB Unifying Receiver Dongle. Since this is USB dongle, it works also in BIOS and during boot process. I'm working with Logitech MK540 Wireless Keyboard Mouse Combo, but there are other models (chipper and more expensive), that will work with the same technology. You ma check also the list of compatible keyboard and mouse, verify by Intel for your NUC.