peripherals? and suggestions?

[ChicKenKen]

I have this PC build planned out, but I dunno what peripheral I should get. Preferrably corsair or Asus. An os suggestion would also be nice. My first build!

 

[TomThePotato]

I'd say Windows 8/8.1, whichever's cheaper because 8 = free upgrade to 8.1. What's your budget for peripherals? and.. What kind of peripherals? Keyboard? Mouse? Headset? Monitor.....?