I have found a pre-compiled package of PDFTK, which did not work by itself. But, after changing some PATH vars, it did.
The files can be downloaded here:
You should simply open the 'libgcj8-1_4.2.4-4_i386' package and extract the lib folder to the destination of your choice (mine was /home/username/lib) and then point the PATH to it. After that, the binary on the pdftk should be running.
The necessary PATH changes are:
I have set my php scripts to run these export commands every time prior to pdftk, and it has worked just fine.
Hope this helps anyone.