Very small room with low ceilings. My system is already very excessive for my current space. I am also planning to keep the system I build for a very long time, probably longer than my current house. Room is about 12x8 with 7' ceilings. Our house is very open so it is also used for playing music throughout the kitchen etc, about 500 sq ft.
I use my desktop as my main media center in the Livingroom. This system will be used to watch movies of course, but also just basic youtube etc. I listen to a lot of old music and instrumental assemblies which is why I am drawn to large cabinet monitors. A few years down the road I may hook them up to a proper stereo tube amp. My center channel and media center are Walnut so if I get old speakers of same wood it should go well enough.
I have a smart home setup and part of upgrading the receiver is to roll it in to the network and use it as a main speaker. I also need the receiver to do 4k 120hz to match my LG G1 panel.
Currently I am looking at the Dennon AVR-960h, the Onkyo TX-NR6100 or Yamaha TSR-700. I am seeing KG4's for about $500 on ebay and a pair of KG4.2 for like $400 which is really tempting. But recently I have seen some older Heresy auctions with the pair going under $1K including shipping. Maybe I should consider spending more since I plan to have them for a long time.