I'm not sure what you mean by cost-effective resources, are you wondering what things are worth investing into inside of a total budget versus which things you could be more frugal on? Overall I would say there's not a big difference in terms of what to consider differently from running Windows: Linux will benefit just as much from good hardware (maybe more?) as window as will.
If you want to do plex and utilize hardware video transcoding you'll probably want an Nvidia GPU but I've had better experiences with AMD graphics cards in Linux. The best home management tool I can recommend is home assistant, and it doesn't have particularly high system requirements, you can run it on a raspberry pi.
I can't wait for this. I've gone down a few rabbit holes looking into solar and battery storage, and even just battery storage by itself to replace the generator we have for when power is out and/or to offset peak use time rates. But batteries are really expensive and I've already got a hundred kilowatt hours sitting in my garage.