I'm afraid that right now Espruino won't work with anything except the W5500 chip. It shouldn't actually be a big deal to use the W5200 instead (and someone was looking at this) - it'd require a recompile of the binary though.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I'm afraid that right now Espruino won't work with anything except the W5500 chip. It shouldn't actually be a big deal to use the W5200 instead (and someone was looking at this) - it'd require a recompile of the binary though.