Private GNU/Linux on a stick with data saved on another
Now I am looking for a rather easy distro that can be kept well on a stick. Only it has to have some extra features. Like truly made for a live system. Meaning less, if possible none, writing on the drive. Compared to a DVD live distro I'd like to be able to upgrade it and enhance it with further software packs. The list won't change over time, but, from experience, I always need to add something. It should let me change the config files. And all my work will be saved on a LUKS drive, another drive. Of course, the config files would be nicer to stay on the encrypted drive.
Most, if not all, the time will be spent off-line. So it's mainly for off-line use. But the drivers should be quite diverse as to facilitate my move to different computers, with which I do not want to interfere in other way than boot my drive. Thus security upgrades are not as important as usual. But there should be a firefox able to take some extensions in order to read offline material. I'm having in mind at least EPUB and MAFF.
I already found Tails doing some of this. But Tails is rather sensitive to changes. As it should be. There also seems to be a Ubuntu Privacy Remix, but it's too old and does not reach the graphical interface on my hardware.