Getting a pi 4 8gb and will set everything up again. Let me see if I can make a guide for you. I will also be migrating from an an as card to a ssd. Apparently it’s a lot more stable in the long run.
There are lots of YouTube videos that explain how to set up homeassitant.
You basically burn the HASSIO image onto an SD card. Plug the SD card into the PI and power up, then everything is done from a browser.
For the inverter node red setup I use a pi 3b. For this you need to log in to the pi either directly or through something like RealVNC. You just need to configure the ports correctly once and then node red is also just done from a browser. Don’t need to log in to the pi again.
Some of the users on the other side have created new flows that publish directly to influxdb and grafana so the home assistant configuration becomes a little easier to set up. Will try it out and see.
Give me a few days and I will then get back to you.
Regarding the pylontech cable, I’m sure the same pi can be used. I’m using 2 interfaces on my one to get the data from both the inverters. It’s just another serial port that is configured.