I use one of these which I got from AliExpress along with one of these, though of course it will work fine with mouse and keyboard.

(Please note that I haven’t tested it specifically with a bluetooth keyboard and mouse).

I installed Lubuntu on it because it’s a lighter distro (it will work fine with the full desktop Linux distros, but why waste computing power on fancy window managers for something that’s just a TV Box that’s always showing Kodi) and have it always turned on (the TDP of this is pretty low) with Kodi as interface and its runs perfectly.

It’s sitting on my living room under the TV.

It’s probably a little overpowered, but that means its fan almost never turns on (it’s pretty quiet when it does, but silence is better), so I’m also running a bittorrent server on it with an always on VPN, plus it’s my NAS. There’s room for more if I wanted.

I don’t really understand people advising the more powerful Mini-PCs: they’re way overpowered for the job hence needlessly expensive plus the TDP of their processors is way more than the N100 in this one hence it both consumes more and is a lot less quiet because the fan has to be bigger and running a lot more often to cool that hotter processor down.

PS: Also the downside of using old PCs for this as some recommend is their higher power consumption, even for notebooks, plus they generally don’t really look like a nice TV-Box to have in your living room, which this one does. If you’re going to run it all the time, a low TDP mini-pc will probably quickly pay itself over using an old desktop, longer if versus an old notebook.