Ethernet interface

I want to add Ethernet to my Mega 2560 project. I want the RJ45 to be accessible at the back of my project box extending through the backplate but I would rather not have the 2560 there. A "remote" interface seems to be better for my application than a shield. Any ideas?

https://forum.arduino.cc/index.php?topic=639043.msg4326715#msg4326715

or https://www.wiznet.io/product-item/wiz850io/