This is the 4-channel version that most enthusiasts have bought, as it’s the one Aaron Productions demonstrates in his video on them:
4 Buttons Triggered MP3 Player Board with 10W Amplifier and Terminal Blocks | Electronics123
I however decided to purchase a 20-channel version after learning there was one (& after I had already bought the 4-channel version). The main advantage with this version is of course more channels for more messages, but I think it also pulls more amps than the 4-channel version when active (thus requiring a beefier power supply to power it with):
20 Channel MP3 Sound Board with 2x15W Amplifier | Electronics123
There’s also smaller versions of the 20-channel model, one in a nice neat enclosure, though I haven’t tested these versions:
20 Channel MP3 Sound Board with 2x15W Amplifier | Electronics123
20 Trigger Inputs Miniature MP3 Sound Playback Board with 2 x 25 Watts Amplifier | Electronics123
For all of these you will need an SD card to supply the board with the messages you want it to play (though for the 4-channel version you’ll need a micro SD card specifically, along with an adapter so you can plug the latter into a computer).