Hey @ejlane! Many thanks. I didn't see your message from a while ago (don't seem to get these in my email). I just ordered the PCB at JLCPCB.com. Worked great! Thanks again. Looking forward to building this gateway.
RFM69 and Ethernet shield share SPI bus, each one with its own CS line. Ethernet shield uses pin 10 so JP1 should use pin 6 for the radio. Issues sharing SPI bus seems to be due to bad SEN line handling as described here. The official Arduino ethernet shield suffered from this, but most commonly used clones work ok. Shields including 74LVC14 as in the pic should work ok.