I don't know of a build thread however, Dave (and later I also) did chronical some of his build here:
http://www.peachparts.com/shopforum/diesel-performance-tuning/290694-om603-semi-super-pump-testing-fitted-bosch-6-0mm-elements.html
and another member posted some of his updates here:
http://www.peachparts.com/shopforum/diesel-discussion/375617-om603-722-6-w124-adventures.html
There are others who have made changes to the 603-powered cars at different levels, these are the ones that come to mind first.