This one with Plasma Mobile would be really nice. The only combination so far I would replace SailfishOS and Jolla with.

Librem 5 – A Security and Privacy Focused Phone

Librem 5, the phone that focuses on security by design and privacy protection by default. Running Free/Libre and Open Source software and a GNU+Linux Operating System designed to create an open development utopia, rather than the walled gardens from all other phone providers.

A fully standards-based freedom-oriented system, based on Debian and many other upstream projects, has never been done before–we will be the first to seriously attempt this.

Purism and KDE to Work Together on World’s First Truly Free Smartphone

Berlin/San Francisco, September 14, 2017 — Purism and KDE are partnering to help KDE adapt Plasma Mobile to Purism’s Librem 5 smartphone.

KDE develops Plasma Mobile, a free, open and full-featured graphical environment for mobile devices. Plasma Mobile has been tested on several off-the-shelf devices. However, most smartphones include hardware that requires proprietary software to work. This clashes with KDE’s principles of freedom and openness. It also makes building difficult, since many details of the hardware are kept secret, preventing complete access to all the components.