Raspberry Pi 3B+
RPi 3B+ is hands down the best*. No competition with the other pies. Especially networking speeds are significantly better than even 3B and it is silly to even
compare it to RPi 2.
You'll need "RaspberryPi Power and Hardware Collection" to make the RPi seamlessly work with your JellyBOX.
If you don't know what to do with all this, you probably want our "Plug and Play OctoPrint-IE KIT" !
(*RPi 4 is a beast of a computer, but too power hungry for this application, and the firmware for remote access is not stable for RPi4 yet anyway.)