I am running a non-lightning node on another pi4, has been running for approximately 3 years. It has a huge hdd attached to it, but no issues in operation.
I’m new to #lightning so I was hoping the deployment would be similar
Discussion
HDD or SSD?
Lighting will add extra CPU load and disc access load. Not a lot, but a bit. I know that it can be done, but I think you'll eventually run into issues. Give it a crack if you can persevere and don't mind upgrading soon.