What about buying a Chromebook? They're cheap, available locally from France,
and compared to ThinkPenguin, Chromebook's BIOS'es are based on Coreboot.
Also, all the post-Pixel models (including the Pixel itself) comes with
SeaBIOS, which means that you can directly install Trisquel without any
workarounds.
Depending on your budged, I can recommend you the HP Chromebook 14 (EUR
315-324), which comes with a nice big screen, and a great price/performance
ratio. It's also the closest you can get if you want a recent free software
laptop. As always, there are some downsides:
- an "OS verification" screen will pop-up at every boot-up (use suspend,
flash a custom BIOS, or just press Ctrl+D to skip it)
- the SSD is mSATA (upgradable, but will cost you much more than a regular
2,5" SSD; use an external HDD)
- touchpad may not work as good as in ChromeOS at first, but this is common,
and can be fixed
- the 4GB memory is integrated (this doesn't really matter, since the
capacity is sufficient)
- the integrated bluetooth chip is non-free (like the AR5B195, which comes
with Gluglug X60; use an external BT dongle)