You may want to take a look at these sites if you haven't already:
http://tunacan.net/t4/
http://www.shoptalkforums.com
(type4rum and aircooledtechnology forum)
http://www.aircooledtechnology.com/
Once you start to stroke a type IV be prepared to outlay some serious cashola. Add another good chunk of dough for the porsche fan/alternator. Not trying to discourage (I'm in the middle of a relatiely stock typeIV upright conversion), just be prepared. Not that Jake Raby is the typeIV god, but he has done a lot of dyno tests to back up his opinions (not just opinion with no evidence) - he doesn't rate the porsche fan conversion that highly (but of course his DTM shroud is recommended)...just do your research, thats all.
Alan