To echo others, If you are exclusively using it to be hooked up to a TV, there are better options. If you want to hook something primarily portable that has the option to hook up to a TV, the steam deck is pretty good.

If you don’t care about portability,

the Youtube channel Retro Game Corps has a spreadsheet of mini-pcs that he’s tested that will give you a good overview of what the chipset can do.

Link to his website where he goes over some advice for buying:
https://retrogamecorps.com/category/mini-pcs/

Link to the spreadsheet:

https://docs.google.com/spreadsheets/d/1nfmESc0IbpT6OCws7irEId41aR1T2m2xj9Fp4jKOq0U/edit?usp=sharing

Emudeck, the tool that installs and sets up all the emulation stuff for you, has made an import/export tool for that. I’d recommend checking that out. Steam cloud saves are your friend for most saves. If the game doesn’t have cloud save, you’ll have to find where the save file is stored and transfer that to your sd card, then transfer it from your SD card to your new deck. That’s probably the easiest way if you don’t know Linux that well.