>However, there's a technical hitch. Nightly-builds are designed to "always"
>built from "master" branch. 

Slavek,
can't we modify the script to build from a given tag instead?
We could use a text file to contain either "master" or the tag name, then the script will read the config file and checkout the version from git according to the settings.
This way, we can switch between master and other tags seemlessly and we don't need a separate PPA for building R14.

  Michele