A little note, not all Nokia 5110 displays and ethernet modules available on the web have the same pinout.

So is there perhaps a detailed BOM for these two items or links to a source with the correct pinouts for this project?

The displays on the red PCB with 2 pinheaders seem to be ok. The ENC28J60 ethernet modules seem to have many more varieties .

The ones sold as “mini ENC28J60” seem to have the correct pinouts, the bigger boards have the SPI connector 180 degrees turned. and some have a mirrored SPI pinout.

Also is it an option to use an arduino nano? Since many already have a few of those at hand, they are just as cheap as a Atmega328 chip and have a USB included. Not sure if the AVR .hex firmware is compatible to do this? Thats why I ask.