There are likely many people who would be happy to chat with you about it. Hopefully someone else here can chime in w suggestions or offers.
Re PC vs Pi I cannot speak to this I have always used RPi and never had any hardware issues and they work great. A simple web search “allstar node build” turned up a site with lots of good info- https://allstarsetup.com
There is also a nice full duplex build that was shared here on the forums recently using PC hardware-
So much info online these days- a YouTube search came up with many helpful vids. Some mention “headless” which is a node you use without rf/radios. Most folks prefer to use a radio (I sure do). You will also see “full duplex” mentioned. This is a radio setup that allows rx/tx to occur at the same time so you can hear if you are doubling or send dtmf commands (like disconnect) while the node is keyed up with audio coming in from the node you are connected to etc.
https://www.youtube.com/results?search_query=build+allstar+node
73
Clifford