I want to configure Grub to pick an specific Kernel version until I change it. But how?
Documentation is most welcome and appreciated.
Install grub-optimizer from the software center and start it. It will let you set the kernel to boot and many more settings.
Without grub-optimizer: GRUB can be set to boot from the kernel it booted from successfully the last time you booted. So that would solve your problem with just a setting.
Use an editor to open /etc/default/grub
and change ...
GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true
Save and update grub with ...
sudo update-grub