here is the best place to research your options...
http://tunacan.net/t4/
DTM
would have been the best option for you were they available at the moment. they are not.
the most complete, non-911 kit, is sold by Sharpbuilt. their URL is on tuna's links page. not going to be too quick there though as they are in Australia. customspeedparts.com (Germany and US) also sells one, but with no shroud. you have to supply that and i believe do some fabbing on it.
one last option is check with oliver in the germanlook.com mall. jake will not do just cooling solutions. not sure if oliver will either, but worth checking.
there are no real quick solutions with a TIV. read tuna's site and you will best understand your options.