I just built a Bitcoin node/Lightning node using a Raspberry Pi I bought on Amazon. I think I will build this BTC Payserver too. Looks pretty interesting. This is what I bought.
CanaKit Raspberry Pi 4 4GB Starter Kit - 4GB RAM
Pimoroni Fan Shim for Raspberry PI
You don't really need this display as Raspberry has a hdmi out built in for monitor.
kuman for Raspberry Pi 3B+ TFT LCD Display, 3.5 Inch 480x320 TFT Touch Screen Monitor for Raspberry Pi Model B A+ SPI Interface with Touch Pen SC06
(edited)
Just realized that I can use the Lightning node I just built for lightning micro payments just like BTC Payserver. Way to go me.