The correct link is actually the one I gave earlier, I am pretty sure of this :)
To build PySide on Linux, you will mainly have to follow what is explain in the INSTALL file for Windows since the build is supposed to be cross-platform. It consists in launching the build.py script that clones the needed repositories and execute cmake inside each downloaded modules (shiboken, PySide, PySide Tools).
I will try on Linux to see if there is any special tricks to do and will give you the way to proceed.
Yann