Building a Retro Gaming Setup with Raspberry Pi

I'd recommend RetroPie with a 32-64GB USB stick.

For controller, a xbox One Bluetooth one is optimal.

To get the roms organized, stick in the usb stick and run the usb-script (https://retropie.org.uk/docs/Running-ROMs-from-a-USB-drive/)

now you can load all your roms.

If you connect it to the internet you can also update all the emulators through the "Retropie setup" option.

the Rpi4 takes micro-HDMI -> HDMI, so your TV /Monitor will need a HDMI outlet.

also get a good enough usb C charger for the pi4, the official one would work.

Side-note, retropie uses launchbox so when you load your roms on the usb it will automatically load in launchbox and get organized by system.