A recent PC Welt article described WinReducer which may be of interest to you.
This is a utility that allows you create bespoke Windows Setup files (.ISO or a USB drive). It also creates an AutoUnattend.xml file for you.
It is not too obvious how to get started and the Tutorials link did not seem to be working on the site, but you can watch a Video here.
It does nag you to Activate (purchase a licence) a lot too!
I still haven't worked out what the difference is between ES and EX versions!