Whonix only runs as a Virtual Machine. There is no way you can INSTALL it as a stand alone Operating System.
There are two ways of running Whonix. Qubes or Virtual Machine. Qubes is kind of hard to get accustomed to if you are not a fan of new UI and if you are unprepared a new, overhauled experience with a Linux distribution. I like Qubes because it gives you many options. You create what they call 'Domains' which are pretty much Virtual Machines. You can create a Windows 'Domain' with no Internet connection. All Domains are separated. They do not interfere. Any USB you insert has to be assigned to Domains you want it to be assigned to. Any thing you do is pretty much happening in separate Virtual Machines and Qubes is just an offline desktop to manage them. Think of it as running multiple computers all on the same monitor.
Best part of it is that the main management desktop known as dom0 is offline while you can run online Domains. With this being said. If a Domain is hacked it is almost impossible for the virus or hacker to get to dom0 let alone another Domain. It is overkill like you say however. Unless you truly care about top notch Security.
Like I said however. It is hard to get accustomed to it. You will have to do a lot of documentation. Reading their install documentation is very important too. You will learn a ton of important things about keeping high levels of Privacy and Security while running Qubes.
Qubes offers full disk encryption in the Install GUI and is extremely Privacy friendly. It has pretty big system requirements however. There is an exhaustive list of computers tested with it. Maybe it is helpful to you.
https://www.qubes-os.org/hcl/Now that I wrote this all I realize I sound like a walking Qubes advertising billboard!
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Tails is fun and all but because of its amnesic properties it is not a great Operating System for daily use. It was not meant to be a daily driver or to be used occasionally with Persistent Storage anyway. So I do not recomment doing a Persistent installation of Tails. What I like about it is the amnesic property of it. But this makes it only a great temporary Operating System. It is perfect if you need to quickly boot up Tails for an Internet search.
In some cases Tails is more secure and can offer more Privacy than Qubes can. But for your needs this might not be it. Would not recommend any body to run a Full Node on Tails. Defeats the purpose of Tails and probably builds loop holes too weakening the Security you should have.
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Since you are looking at some Debian distros. Why do you not just install the blank version of Debian? Download and install only the first CD file from
https://www.debian.org/CD/http-ftp/. That will install the most stripped version of Debian. Last time I checked, the stripped version of Debian is 100 percent Open Source. Then you can install any non free driver or package you like by downloading it from
https://www.debian.org/distrib/packages. This is the most hard core way you can go if you do not trust any thing and any body.
What I like about Debian is pretty much ANY issue you will ever encounter with Debian will be about one or two quick searches away. There is an entire community for this distro. It is Debian after all.
Warning. This means you will encounter a lot of problems you will have to fix by yourself one by one until you can get to run the things you need properly.
You will probably not even have Wi Fi drivers after installing the first CD. Probably will not need that if you are using Ethernet any way. You can look up drivers for any thing that does not work. I doubt you will not find a way. Internet is your friend.
But there is a bit of work to do if you want to keep it as clean as possible and this is the best way to do it. Who needs display driver which is proprietary. Who needs Bluetooth adapter. Who needs all that B S. I like it raw.
There are many other distributions but I would not trust them. Fewer contributors and users means more loopholes. Tails, Qubes and Debian are pretty much Top 3 for people who do not trust their computer and Operating System much. Ubuntu is probably the most popular distribution across the Linux community but even Ubuntu is based on Debian. Why run something that has been built on top of Debian when you can run Debian itself.
Other Privacy oriented distributions are more focused on Security than Privacy it seems. Kali and such.
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Or give them all a try. See which you like most. Maybe you fall in love with one and keep it.