I went away from a 5.1 system and use just stereo for a few years now and i watch everything on my pc but dont really miss the surround. Most of the time I use a good set of headphones and an O2 usb amp and dac combo from mayflower electronics if im sitting at the desk.
I got this kit for a new 3900x build. Have not got to test it yet but im hoping for the best.
I got one of these a few years ago and they are good. Sometimes you just have to get down with some qtips and isopropyl alcohol.
I personally like the herman miller aeron chairs. I am about the same size as posted. They are made really well and dont sweat your ass because of the mesh bottom. They usually run you around $400-$500 is the only downside.