TV, it's almost all or nothing and that make the choice complicated,
DVD player almost useless
Sound bar, good things if you watch blockbuster , but for daily and News show no need
Too flat TV it's just for increase the price,
4K , 8K , OLED , DOLBY TV and so on hard to see the difference if you watch TV program, for Film that depend on the source.
Brand: Japanese brand like : Sony , Samsung , LG they have almost all , so choose one fit your budget and that will be OK
Smart TV: this is a nice function but not so many people use it.
Must have: 2 HDMI is the mimimum , Optical can be a good point in the future like USB plug.
That's all i can said
PS: My Home Cinema system include the 105" TV is around 50k £, but only for watch movie from my NAS