While it might be possible for individuals to solve this problem with money, I feel you may be missing the forest for the trees.
OP could just not connect to the internet, job done, right? The issue isn't so much they want privacy, it's that they want us all to have privacy.
It's not reasonable to expect average-joe to know about coreboot, seek out hardware that specifically supports it, then find a collection of browser extensions and communication tools just to have a private conversation with a friend.
Instead we should have regulations in place that make it possible to buy the computer at the local store and talk to your kids online without being monitored every step of the way.
