WASD tenkeyless for the board, steel series sensei for the mouse, Beyerdynamic DT770 Pro or Oppo PM3s with a decent DAC for the headphones.

For the keyboard, it really depends if you prefer form over function. WASD makes some of the best mech boards on the market and has a huge variety of custom key caps. If you want some fancy backlights, the Ducky Shine 3 is pretty cool.

Headphones depends on if you want open or closed back, but I definitely recommend the two I mentioned with even a cheap DAC. Both of those are closed back, which has better noise isolation.

The mouse is a simple, but rugged and proven mouse. Can't go wrong with the sensei.