EDIT: Update - scroll down
EDIT 2: Update - problem solved
re: spawn-php python script...
Thanks @nosam that really helped.
For those wanting to get it working quickly you'll need the following (if 64bit system)
ActivePython-2.7.2.5-win64-x64.msi
pywin32-217.win-amd64-py2.7.exe
ActivePython does not have older versions of these on their www so you will need to do a bit of googling around to find a working mirror (there are plenty out there)
Once you have downloaded the src from bitbucket you may need to edit spawn-php.py (to fix up the tab spacing), as bit-bucket seemed to mess up the tab's in the file preventing it from running.
All-in-all that saved my day for a busy little windows website using nginx + fast-cgi.
Thanks mate!