I've used a tv with a computer for a few years. Currently I have a 49" LG HDTV and connected to my media pic to it via HDMI, and with the graphics card, it easily outputs 1920x1080p. So great for movies, and music videos that I've downloaded and play on it. It's also connected to my amp so get 5.1 sound. I have the DPI set to 125% so that I can view the icons and task bar easily. I have a similar set up in the kitchen and also the bedroom albeit on smaller screens. It has an SSD so it boots in 15 seconds from power on. I also use Kodi and with addons view many additional films and to series., and handy to show family pictures on and play music, Internet radio etc. The 'ribbons' screen saver looks ok on a big screen too if you decide to keep the to on whilst listening to music.
So it's easily done and you don't need a top of the range pc to do what you are looking for, if you have a media pic style case, you may need to look for a 'low profile' graphics card so it will fit in the case. I also purchased a blu Ray drive but since copied my DVD's and Blu Ray to my server pc and stream from them to the other PCs around the house.
I'm not sure what it would look like on an UHD tv. Only the latest video cards will output to the resolution of UHD and they are pricey. Ask around and see if anyone you know has a computer connected to a screen but doubt you won't find any/many connected to UHD tv's.
Drop me a PM or post again if you need further help.