If it’s an online shop, I recommend using a Bitcoin payment processor that supports Lightning for the same reason of unbeatably low fees. My recommendation would be to use
https://btcpayserver.org/.
There are 'node in a box' setups.
raspiblitz:
https://raspiblitz.org/MyNode:
https://www.mynodebtc.com/That do most of the setup for you in terms of setting up your own
BTC node / lightning node / btcpayserver.
For myNode, btcpayserver only available if you use premium version (cost $99) or you bother setup it by yourself.