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.
You still have to know what you are doing to get it integrated into your store but they do get you most of the way there.
And both have active support.
-Dave